Reduced engine power on a 2008 Grand Prix

You are in "Limp mode" ....give me a few minutes to look in to this.. how to get it out..unless Tom or somebody knows offhand?

Take it to a mechanic that can scan the sub-computers. They may be able to tell you exactly what triggered that light. And you are right.. There are a ton of things that trigger that light.

Thanks! Do you guys think this could have anything to do with my accident in march?

Okay...whatever the reason OBD 'told' the PCM to go in to limp is going to have to be fixed first...you can't simply take it out back to full power unrepaired, There is a good reason for that, to prevent more damage to your drivetrain. Limp mode is to get you off the road, if there is a big parts house near you...no more than a couple/3 miles, limp there and get your OBD scanned and bring the codes back here, if there is no place near you to do so, beg, borrow, buy, steal a scanner.

About related you accident 4 months ago, doubtful. And I was typing at the same time as Michael..he is right on target.

krizzio89, Have you had any luck getting this resolved since your last post? If there's anything we can do to support you as you seek to get this resolved, let us know. Sarah (Assisting Marlea) GM Customer Care

I have a 2006 grand prix, and the signal came on last night, reduced engine power, haven't had a chance to get it on a scanner but I will, and will post the results.

I got my car towed into a shop and they said it was the electric down by the H-frame. When I went in the ditch in March the h-frame was replaced and the people who did it did not wire it back up correctly so in my case it wasn't the throttle body or anything like that it was electrical.

i am having the same problem got the scan done and was told error code was p1125/p2138 and p1516., per the read out the cheapest fix for me is the app sensor but not sure where it is located on the car.

this justhappend to my girl car the reduce signal light is for climbing steep hills but that meens traction con troll so to me it sounds like the traction sensor is going out i looked at the car book for the signal it say when the car shut off to press reset and hold set button but only when the car is off and i did it it worked but only for a two block radiouse never seen that be for but its sounding like the traction controll and did any 1 change the pcv valve b4 this problem happend it happend the day after hers was changed.

My 08 grand Prix does the same thing. I was told it was my app sensor whichis on the accelerator assembly. They also told me you have to change the whole assembly in order to replace the sensor is this correct?

yes that was what i had to do.

My 2004 Pontiac Grand Prix GPT has done thee exact thing 3x now! Two of which I was driving on the highway! Traction control disabled light first, then engine reduce power.. Acceleration drops so I have to pull off the road ASAP! Car cuts off, I simply start it up again and it's fine. Scared the crap out of me. Can anyone tell me what exactly is the problem so I can get it fixed ASAP? Also I just heard about the big GM recall. I hope that my car is on that list and they will fix it. I love my car but it's driving me crazy ! Lol

Man I'm going through the same problem and need help my 05 gt keeps going to reduced power and traction control off mode. I got codes p1125 p2120 my machine says the acc position sensor has already been replaced. Some tried to fix this problem b4 I bought the car but failed. HELPPPP

I have a 2006 Grand Prix as well. It is in the repair shop as we speak, racking up the repair dollars. They tried replacing the throttle body today, but it didn't fix it. Now they want to replace the ECM (computer), but I recall some feedback along the way that says this isn't likely the problem. My car was "disabling" the engine so badly that I could not continue driving. I had 5 stalls on the 1/2 hour drive to the repair shop.

My 06 is doing the same thing dealer said it was throttle body. It wasn't throttle body. Was wondering if the new ECM fixed the problem

My car is still in the repair shop with a dispute over the $1,600 bill for both a throttle body control module and main computer. They are saying it is now fixed. I got a fast one four years ago from the local GM dealership (when they should have replaced the main computer as indicated but they denied it was on warranty + +) so I'm digging my heels in. I am also a little worried that this doesn't solve the problem for good - maybe another main computer (same faulty product, essentially). But, for now, definitely the main computer (PCM aka ECM) is the identified fix. Same deal, fixed the throttle body module, it didn't fix it, then replaced main computer. I am real angry with GM head office for not rising to the occasion here.

Thank you for the info. Don't let them charge you that much , they wanted to charge me $800 just to change the throttle body on mine. I found an ac delco online for $180 brand new and it took 20 minutes to change. I found the computer on line for $100 to $200 brand new. Iv had mine out but haven't replaced it yet it only takes about thirty minutes to replace and a few minutes to reprogram. I won't ever go back to the dealer and I will never buy another gm vehicle because of this.

Well now, let's see.... I bought my 2008 Grand Prix only a month ago. And of course I'm having the same problem. After reading all these posts... oh man. Very discouraging. I was going to hook mine up to a diagnostic machine this weekend. I really hope its not going to cost me my paycheck.

My 2008 grand prix just did this to me today. My reduced engine power warning came on then my engine light came on. I was driving couldn't go faster than 20 miles per hour. I pulled over turned it off for a couple of minutes then turned the car back on and it was fine but my engine light is still on. It is safe to drive? Calling the dealership where I got it from on Monday to put in shop. I just had the resonator and converter replaced in the car.

This has been happening to my husband's '08 g6! Replaced some oil cap and battery. Didn't fix the problem. Curious to hear about if it's the ecm.

to fix my problem with it they had to replace the accelerator assembly. had them fix it then traded it in 2 weeks later so not sure if it actually fixed the problem.

My reduced engine power warning came on, but my car is driving as normal. Do you think it's okay to ignore it unless other symptoms occur?

I'm so confused with this reduced engine power signal there is a arrow that is pointing at the engine but after having them put it on the machine I'm only getting bad sensors Confused Help .were can I find the recall information?

My 06 Grand Prix was saying sensors and wires were shorting out. The dumbass dealer wanted to screw me over and charge me thousands of dollars to change everything and fix all the shorts. But I didn't let them . I went to a wrecking yard and found a used computer off of a 08 Grand Prix for $50, and put it in then took it to the shop and had them reprogram it for $40 and the car has been running fine since. There was no recall on my car I checked several times. You can call your local dealer and give them your vin number and they will tell you if your car has been recalled. Most likely not they must be waiting for more people to die before they recall our cars.

so i just changed my whole pedal and I think the new pedal comes with the sensor.. and my car has the problem. reduced power engine and the checking engine light. I cant drive my car. I don't know what else to do since all that show up in the scanner was the sensor. the mechanic told me to take it to the dealer that maybe they have to reconfigure my new pedal or something?? I need help.. before taking it there..

This seems to be a very common issue...I just bought a 2007 Grand Prix and was driving to work and the it said low power...what's going on?? And why does it seem like everyone is having the same problem?

I have a 2008 Pontiac GXP Ann is doing the same thing reduce power to engineis this something that g_m didif you let the car sit for 2 daysand it'll drive fIn for another few days what is the problem

Just had this happen tonight on my 06 grand Prix. Check engine light and reduced power mode came on at the same time. Limited car home and cleaned out the throttle body. Cleared the codes, drove around the block and issue came back. Now looking into the accelerator since that code is coming up as well the manifold. Any suggestions before I start shelling out money for parts?

I constantly fail myself every time by purchasing these GM vehicles. I'm starting to believe these vehicles are design to create these problems after so long/ many miles. I have read everyone's response but no one actually knows or have the solution to the problem. The one person who would have the solution to the problem is the dealer, but by looking at some people comments, the dealer is correcting a throttle problem which is not even the case. It has to be a better way. REDUCED ENGINE POWER light is on, Help.

UPDATE: After cleaning the throttle body, only 2 of the original 4 codes came up. Throttle position sensor and Accelerator position sensor remained. Picked up a new gas pedal assembly from a pick-n- pull and swapped it out. Also, found out that after you clean the throttle body you have to go thru an "idle relearn" procedure in order for the car's computer memory to stop compensating for when the throttle body was gunked up. So far, car is running better than before and no more check engine light or reduced engine power display. Whether it was the new pedal or the relearn procedure, I can't answer that. I don't remember where the info on the 'relearn procedure' was at, but I do remember it mentioning that if the 4th letter in your VIN# was a W, this had to be performed. Good luck!

I have a 2008 Grand Prix only for one year with 92,000 miles on it. First it was the high beams that would come on with the turning signal. Now the car has the Reduce Engine Power light come on, then check engine light and I can't go past 20 MPH. After reading everyone is havng the same problem. If I have to spend a lot of money to get this fixed, I'm definitely trading this car in and never going back to GM. I usually get foreign cars. No more american made for me!

So I took my car to the shop and printed out all the comments. After the diagnostic they said it looked like someone who didn't know what they were doing did a lot of jumps off my battery recently and that ruined my computer. I have only had the car 1 year and haven't given anyone a jump off my battery yet. He said the computer alone would cost $468 and he would not put in a used one. I looked on line and the first search led to the part with a limited lifetime warranty for $200. Does every mechanical shop hold this policy? He wouldn't fix it unless I let him by the part for $468. I am pissed!

some shops will part a used or your part in, but then they wont guarantee the work

This just happened today on my 04 GTP with 130k miles. I will post what I end up finding.

mine was a new under the hood fuse block, which has all sensors two- sensors seem to a problem with this type of a car..car junkies is a great place for advice to

Don't have an answer but I'm having the same problem. I have a 2007 Pontiac Grand Prix. My high beam light keeps coming on with the signal. Last night my car slowed down. Then reduced engine power came on. Seems no one has a solution. Help before some one gets seriously hurt.

Had this issue with my 04 Grand Prix. When in park, I'd press the accelerator and it wouldn't get past 1300 RPM. When driving, we would have to take off very slowly after a complete stop and even then, couldn't go past 65 mph. Replaced the mass air filter, the computer, and pedal/accelerator position sensor. None solved the issue and the car would still show the "reduced engine power failure" thing. Finally took it to some dude that had a $6k computer error reader thing and it came up with the throttle bottle assembly. After spending money on all this other stuff we said why not, so we went ahead and changed it. It cost a little over $300 at the local auto parts store ao we went to a junkyard/you- pull-it place and found the car we needed. We took it off right then and there. It doesn't take but 10-15 minutes to get out and put back in. all you need is a 10mm socket and git r done!! Sparked up the car and BAM!! We were able to press the gas and it picked up right away. It's been working fine for a small trip now and looks like this fixed the problem!! It was the throttle bottle assembly. When we took the original one out, the gasket was totally worn out and looked pretty ugly. That may have been it but just replaced the whole thing. Good luck!!

TRY THIS: I have a 2008 PONTIAC G6 base model sedan that cut out on me on the highway. I heard 3 dings at the same time my engine light came on and the read-out on the radio was "SERVICE TRACTION OFF/ REDUCED ENGINE POWER". My neighbor who happens to be a mechanic told me to get some HEET and Sea Foam cleaner and pour these in my gas tank to help get rid of any water. He also told me to get some GUM-OUT and clean around the flap on the throttle body but be careful not to spray to much while cleaning. This happened today Jan. 7, 2015. My car is running fine now.

I have a 2004 Grand Prix with 180,000 miles on it. I got the engine light then the reduced engine power and service traction control lights. It had read 2 codes p0068 and p0101. I cleaned the throttle body and MAF sensor which didn't help. After inspecting the MAP SENSOR I discovered that it was broke, so I replaced it, and that was it. I had to disconnect the battery for 30 min. to reset the computer to get it out of limp mode. Good luck

I have a 2004 grand prix gtp and the reduced engine power is happening to me along with the service stability control system there were two codes coming up one was the throttle body actuator module and the second code was the EGR valve first I cleaned out the EGR valve and then it kept happening so i did the relearn procedure for the EGR valve and now that is gone but the throttle body code still comes up I cleaned that as well does anyone know of a relearn procedure that works for the throttle body?

I just went through the same thing and it wound up being a missing O-ring on the MAP assembly. I had changed the PCV valve for a smog and somehow lost the O-ring, which finally corrected my problem. as far as a relearn for the throttle body I don't know of a relearn, but try pulling the battery neg. cable for 30 min. which will reset the computer. the computer should self adjust.

Thankyou I will look into this. it seem that the problem occures mainly late night and when it is cold outside

OK, that particular vacuum leak caused my car to go in limp mode whenever it was icy out good luck

9 times outta 10 it's a Cadillac converter and hurry up and get it fixed because it'll make your transmission go next

Oh yeah and it should be somewhere round hundred forty bucks to get it fixed

Also check your PCV valve your throttle body sensor your coils and your ignition module

So guys i posted long time ago about my car not working well because it would say that my engine power had been reduce and the scanner would say was my pedal sensor. So i took it to a mechanic i Knew and he changed the spark plugs that were the ones that came with the car when the first owner got it. So we changed them and that solved the problem. Now my car is nice and works like always. Good luck.

Still waiting for a throttle body to come in the mail. Cant seem to find a problem with map sensor. Pcv valve changed with full tune up. only code coming up now is throttle control module. Tac. I hope it is not the cat. Converter. I will let everyone know if the new throttle body works.

I took out the throttle body in my 04 gtp and cleaned as far as I could reach, put the new throttle body on, cleared the code with a scan tool with the harness unplugged. hooked the harness plug in and started the car and problem is fixed. No more reduced engine power. Car runs better than the day I bought it.

Im having a similar issue with my 2008 GXP, it has a lot of power as is , but i can push the gas pedal to the floor and the RPM wont go over 4. I put it on a computer and the only thing that came up was the oil pressure sensor. Any idea what else could cause this ?

My 04 gtp had this same problem and had the abs light on I pulled fuse 31 under the hood for the abs and the car hasnt shut off since

My 2008 Pontiac GP kept going into "Reduced Engine Power". It did it just as I was driving by an AutoZone so I had one of their clerks put a diagnostic reader on it and it came back with "Accelerator Pedal Position Error". They had one in stock for $62. Replacement was pretty easy: two 10mm bolts and the wiring harness. It took all of about ten minutes to swap it out and the problem hasn't returned since. I also notice the car is much more responsive with the new accelerator position sensor.

My 2008 Grand Prix GXP similar problem, 1st the Track System service repair light on, brought it in 3 weeks later, they replace front bearing, ($461) and an hour before I brought it to be service, I lost engine power, they cleared engine light for accelerator pedal position sensor. Being cautious for this warning signal to return.

Mine just yesterday said track system off and reduced power. Codes ran back to gas pedal. Got a new pedal and reset my codes and everything was back to normal

I have a 06 grand prix that just did the same thing.I changed the throttle body first but it didn't fix the problem.for me it was the app sensor.I changed the gas pedal.it is two 10mm bolts with a plug at the top.then I used my obd to turn off the check engine light.It's running great now

I have a 2005 G6 GT I bought it used just because it was inexpensive and looked great for the money. Once I had the car for a month or so I started to trust it and now I am slowly becoming in love with Pontiacs this car for 2005 was highly advanced power heated leather seats, power mirrors, sliding sunroof, very comfortable and fairly quick nice chrome 17 inch rims and the monsoon radio is done properly the back speakers as you probably have noticed have 2 sets of wires on each speaker the one set is just bass no words and the other 2 wires control treble and mid range. The front door speakers the little tweeter is set up the sane way so you can turn bass up and get no distortion. EXACTLY HOW IT SHOULD BE DONE. But Getting to the ENGINE POWER REDUCED LIGHT AND THE ENGINE LIGHT AND THE OTHER LIGHT THAT LOOKS LIKE A WRENCH AND THE TRACTION CONTROL LIGHT BEING ON MY HAZARDS WERE EVEN ON BUT THE BUTTON WASNT PUSHED IN!!!! I was freaking because I was starting to love this car. Well anywAy in Florida we had a rainstorm that was the hardest rain I've ever saw like 9 inches IN 45 minutes my sunroof was cracked open a little I had puddles of water my cup holders were filled I thought I was fucked but I pulled out carpet took off all the plastics I could I even had water drip from my dash right above my hood release. I started the car and drove 20 feet stalled put it neutral started it luckily a mechanic who's speciality is electric lives less then a quarter mile away. He said something got wet and was marketing the computer be in that mode he told me to get my car dry quickly I cranked heat. Vacuumed it out and used a air gun to blow off water where I couldn't reach within 2 hours first the light that looks like a wrench shut off the traction control shut off then the reduced engine power LIGHT shut off and I disconnected battery for 10 minutes and it's running like it did before the rain. The technology for that vehicle is ahead of it's time I wish it had dual exhaust I don't get why they wouldn't put dual exhaust on the top model of the G6 Dual exhaust should have been put on just for looks if I see a car and it does not have dual exhaust I don't consider it any type of sports car. Ever since I was a kid I always looked for 2 pipes coming out the back.

I own a 2006 G6. Recently had the fearful experience of driving on a crowded freeway when ENG PWR REDUCED appeared and the car died. I was lucky not have been killed! Now it's in the shop. If replacing the expensive throttle module doesn't fix it, I will JUNK THE CAR. I will not drive a car that dies like this. Oh yeah, turning it off and on fixed the problem ... for a few minutes. Bizarre. Garbage. I will never buy another GM car.

I have an '06 Grand Prix just had the reduced engine power fixed. It was a gas pedal connector. My mechanic replace my gas pedal and everything is great. $200 fix.

Mine was the computer, 2006 Grand Prix, reduced engine power car shut down power stayed on .... These cars have a lot of problems I've had to fix a whole lot.

Hi all , past and future readers . On a 04 - 08 Pontiac prix , gt & gtp models that are series 3 which has a all in one throttle body . Since there is no throttle cables it runs off of a A ,B relay or sinssor. The throttle body is sinssor B ,----> Accelerator Pedal sinssor A. Which is a 80.00$ item , Symptoms bucking,engine fluttering,tracking light and abs on, fuel loss and even stalling out car. Hope this info saves some headache for future readers.

I had this issue with the "Reduced Engine Power" message on my 06 Grand Prix. I shut off the car for about 20 minutes, then pulled off each spark plug wire one by one to check for spark. After checking each coil connection, I restarted the car, and no more problem.

We have a 2005 Grand Prix. We have had many of the fixes mentioned here, including most recently replacing accelerator pedal assembly & app sensor. The problem continues. This has been our experience- the reduced engine power has happened only in rainy weather, or in the aftermath of a heavy rain. Never on a dry day. Anyone else notice this?

There should be a class action suit to address this. Our Grand Prix slows down to 30 mph on the highway sometimes- we are lucky we & our teenage drivers haven't been killed. The GM dealership did not fix our problem- the computer diagnosed the pedal assembly, they replaced it, and tough luck if that didn't help- but they'd gladly take more $ to perform more useless work.

I posted awhile back about losing power between 1k -2k rpm it was fluttering also going up hill. Several thing got replaced - fuel pump which did not fix issue also throttle body, pedal ,fuel filter ,spark plugs/wires and cat which none fixed issue. Took the car in to shop , they had it a day which no codes was showing up on the bcm. They suggested replacing it which I did , which did not fix issue . yea already spent time and money , all my issue was a map sinssor going bad that was not reading under codes . Only reason my car went into limp mode was where I installed new pedal and had todo the relearn on it .

I have a 2006 G6 and after a couple hours of rain tonight when I started it up the Reduced Engine Power and Check engine and No TC lights were on. When I pulled out of the parking space water came dumping inside the car form the top of the windshield and the telescoping sun roof. There is even water in my map lights. An electrical or sensor issue makes sense, like maybe it got shorted out. Will check in the morning and report back. Thanks for all the good suggestions.

To everyone with this problem it is your mass airflow sensor !

Besides the obvious cases where the car has water in any of the electrical. That could then be a short in any number of sensors. The mass airflow sensor would also cause rough starting to not starting at all, it can also cause increased fuel consumption, and causes the dreaded reduced engine speed warning, and in an effort to save the motor the electrical shuts the car down from the user until the problem is fixed

I have a 2006 Grand Prix and for the past month I have spent $800 on my car. The reduce engine power warning came on. The first time I took it to the shop I was told that it was the accelerator pedal. I got that fixed and it was running for a week. The same thing happened again and they told me it was a wiring/ sensor issue. I got that fixed also and two days later the warning came on again. Went back to the shop and they looked at the manual for my car and it suggested that the throttle body needs to be replaced. I replaced it yesterday and got on the highway and an hour later the reduced engine power warning came back on. Now I am very frustrated and don't know if I should be driving this car. Will take it back to the shop today and see what's he codes say this time. I do believe that there is a recall on my car. I have gotten noticed but it was for the starter I believe. I NEED HELP!

I meant to say that I have an ignition recall. Does anyone know if that has something to do with the reduced engine power?

Hello, Im about to order and replace the throttle Position Sensor on my 2004 Pontiac GP base on the following link assessment: https://www.youtube.com/watch?v=C5BEPmFB6cw Part on sale here: http://www.partsgeek.com/gbproducts/MC/4734-07042266.html? utm_content=MC&utm_term=1997- 2004+Pontiac+Grand+Prix+Throttle+Position+Sensor+Standard +Motor+Products+97- 04+Pontiac+Throttle+Position+Sensor+00+02&utm_source=goo gle&utm_medium=ff&utm_campaign=PartsGeek+Google+Base& gclid=Cj0KEQjw7-K7BRCkkIH3t_WwoskBEiQAD8oY3v7bdq9k- UJ9ylLfN58E2Axz7WZieAsCNh7WG0n94xAaAuKn8P8HAQ&ad= 47584901292. I'll let you all know!!!

Ok I had the same issue with reduced engine power code and car shutting down while driving. Once I start it back up it accelerates very slow even when mashing in gas pedal. I changed the throttle position sensor first. Unfortunately couldn't get the sensor by itself had to buy entire assembly (took me 15minutes). That didn't fix it so I replaced the accelerator pedal sensor which included the pedal (took me 10 minutes). Problem solved. Not saying it will resolve your issue but it fixed mine!! No mechanic needed don't get taken to the bank. Look up the YouTube video and do it your damn self. Good luck and hopefull this helped.

Im currently having this issue, they told me i need a new "APP harness". I grt my car back today, ill let you all know if this fixes the issue or not. I took it to a dealership, and they said its gonna run about $570 to fix.

A month later and car still running good with no reduced engine power error after installing accelerator pedal sensor. Just wanted to do a follow up.

I had this issues as well. It is something to do with the gas pedal or the throttle assembly. We took it to the dealership and they diagnosed it to be the Gas Pedal. They replaced it and everything is great now. No problems at all.

I had this same problem just recently before emissions...my check engine light was on with 8 codes a reduced engine power code in dash...I changed the throttle body but that did not so I then changed the accelarator peddle and reprogrammed the computer through a dealer and i passed emissions 2 days later with no problems since

Did you find out what it was

This is an old thread. But I have an 04 Grand Prix and I had this issue a while back It wasn't any sensor or throttle body or a computer. It was simply my catalytic converter. Considering it's a 13 year old car, it was only about time. If any of you are having this problem, check the catalytic converter. It's a pretty easy process. You just start the car and rev it up a lot, then go underneath and if the converter is glowing red then it's clogged up

This is crazy that we are all having the same issue and there is no recall. From the high beam issue, check tire pressure sensor light, now to this reduced engine power. So much for normal wear and tear when all of our cars are having the same exact issue.

I have a 2004 Buick Rainier CXL 5.3 engine, and the other night leaving work my check engine lights came on and power decreased. Freaked me out. I turned off and pulled into a public parking area for a restaurant, in case i needed a tow. Shut off the car and called my daughter and while on the phone i restarted car and drove around parking lot, and it seemed fine, so i drove a couple of more blocks to a oil and lube place that was still open. they checked the diagnostics and it was the P1516 code. Recommended I take to their other place with mechanics there in the morning. When i left the two check engine lights were on but drove okay. Next morning no lights on dash, they couldn't run diagnostic with better machine, so said to drive it until the lights came back up and bring it in. Now I am limited to driving 3 to 4 miles a day for fear of having a bigger issue and being stuck. I use a cane and don't get around to good. So, it does freak me out. Had to cancel a doctors appointment out of town for fear of being stuck out in the middle of the mountains and being too far from anything. From reading previous posts, it seems its okay to drive, because that made me a little anxious, as I was told it could be a wire arcing. So afraid of having an electrical fire. I wished I knew how to fix it. At both places they looked under the hood and took off the housing and looked at wires, and couldn't find anything. Any recommendations for the Buick Rainer, CXL 5 3 engine? Help!!!

Ok so your pedal and your sensor below is all one unit it is a bad gas pedal 100% fix it will run about 112 brand new at auto zone sounds stupid but believe me it's common and it's a guarantee fix

Was just dealing with the loss of power and acceleration had new plug wires and plugs knew it wasn't a clogged injector turned out it was a number 31 code which was a fuse under the hood that tells the transmission what to do plus a dirty mass air flow sensor just thought I might help out

Mine is doing the same thing but once only and I stopped turned it off and it's fine now. But when mine did it it said check trip computer first, the it started going back and forth from reduce engine speed to stability control. What is that?? Wouldnt let me go over 35. Check engine light is still on too.

I have a 2008 Grand Prix. This has been going on for the past 3 years. I adjust the gas cap and the next day it's fine. However this past week, it has happened 5 times. I'm hoping to purchase a new car in August, but was hoping not to have to repair this one first. It seems this should have been a recall on the car, as my mom has a grand prix as well 2007 same thing with her's. So frustrating

I just had an issue with mine a few months ago. Took it in and the guy says that codes were for the same sensors y’all are talking about but he said the issue was that my fuel was running very lean. Not sure if that’s the exact problem but sounds like it may….anyways, cleared the codes, put 3 new sensors in and it’s been running great ever since. Good luck

I just thought I would get on here and let everyone know that the problem with my 2008 Grand Prix base model when it went into limp mode with absolutely no pedal response and rough idle it turned out to be a bad wire in a wiring harness on the driver side just above the strut housing up next to the firewall. It lost the five volt constant when I replaced the battery and in turn couldn’t re-establish the connection due to water damage and corrosion. It was easy to just rewire that one wire and re establish water resistance by electrical taping it to seal it back up. After doing just that I re- hooked the battery up and it fired back up and was good to go.