PO 300 Code

A code P0300 may mean that one or more of the following has happened: Faulty spark plugs or wires Faulty coil (pack) Faulty oxygen sensor(s) Faulty fuel injector(s) Burned exhaust valve Faulty catalytic converter(s) Stuck/blocked EGR valve / passages Faulty camshaft position sensor Defective computer Possible Solutions: If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back. If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors. Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open. Hope that helps

I have a 2006 Dodge Stratus SXT Sedan, 2.4L, 4-cylinder. Started experiencing engine problems for about a month before check engine light came on, after almost 5 years of attempting to repair, I have officially found what was wrong. I took this car to SO many dealerships, private mechanics, anyone who knew anything more about engines than I did, and nothing was caught. From what I understand, from asking around now and researching, these two codes in my 'story' for check engine should automatically cause them to give the diagnosis it took me YEARS to find. For the first 3-6 months with the check engine light, I would consistently check/clear the codes with my OBD2 reader. The code that was shown was: P 0303; Cylinder 3 Misfire Detected. Car ran okay, had a very rough idle, but did great at highway speeds. The best way to describe it is that my car 'thought' it was a manual and that I wasn't pushing in the clutch to stop. Exactly how it acted, and would sometimes even stall alltogether. (Obviously, its an automatic, not a manual) So the idling got worse, and I noticed a HUGE change in my fuel usage. So I decided to hook up the OBD2 reader, since the check engine light had now began to flash any time I started to slow down or stop. Now, it had changed to 4 codes total, but it was just 2 repeated. They were: P 0303; Cylinder 3 Misfire Detected, and P 0300; Multiple Random Misfire Detected Both codes were being thrown twice, I'd clear them, and the second I'd start the car they'd come right back. THIS IS WHAT SHOULD HAVE BEEN CAUGHT YEARS AGO, WHEN BOTH CODES APPEARED. THE DEAD GIVE AWAY TO THIS ISSUE WAS THE SAME CODES BEING THERE MORE THAN ONCE, AND BOTH OF THE CODES BEING IN THE 300s. I started with replacing plugs and wires, my ignition coil pack, I literally replaced everything that said could be causing one of the codes, not both, and not both together thrown twice. FOR 5 YEARS, it was my DAILY driving car, come to find out the issue is a burnt valve on cylinder 3. I drove the entire time, making it worse, and having no idea because I trusted those who I thought would give me honest and truthful answers, obviously since they got me to replace things that I knew dang well I had already done or had nothing to do with the symptoms my car was showing. DOUBLE CODES IN THE 300s SHOULD BE GENERAL KNOWLEDGE FOR A MECHANIC, ESPECIALLY WITH THE SYMPTOMS OF VEHICLE ADDED. EVERYONE I TOOK IT TO MISSED IT, AND CAUSED ME OVER $1,500 IN DAMAGE. ASK THEM FOR COMPRESSION TEST ON CYLINDERS AND TO DO WHATEVER KIND OF VALVE JOB THEY OFFER, PREFERABLE BOTH ON INTAKE AND EXHAUST VALVES *TIP/TRICK/HINT* If you have the same or similar 300 codes (if you've checked the OBD2), or if your vehicle is acting up, especially with the rough idle and then being fine at highway speeds, have someone you trust and has the equipment to check 2 things before you either 1. Spend WAY too much money replacing things that don't need it, or 2. Drive it daily and cause WAY more damage than it started with. The 2 things to have looked at are to 1. Have a compression test done on either just the cylinder causing code or test all of them, 2. Have them do a Valve Job on either or both the intake and exhaust valves. My Cylinder 3 valve has been BURNT this ENTIRE TIME, from the misfire DETECTED. When the valve started to warp and burn, that's when it gave me 2 of the P0300 Multiple Random Misfire. If I hadn't been able to figure this out, no doubt I would've caused my own engine failure from driving it.

I had that exact error for like 3 months, I checked everything, literally, then two days ago, I changed my car oil, then my dash started to flash oil change logo and air bag together with chime/bing sound, It's so bagging that every 3 secs will bang, then I took the car to my trusted mechanic, he asked me few questions, He asked me when this started to occur, I told him few months ago, but bagging sound two days ago when changing oil with filter, he told me that I have counterfeit oil filter, I told him no way, that oil change station is trusted, he told me to go get genuine mopar filter from mopar directed, I did so, and my problem was instantly solved! the station was a total fraud, he sold me exact look counterfeit oil filter, I can't sue him now cause I don't have receipt (He actually always avoiding making one), from now on, I will bring my filter and oil with me, and I'm thinking about changing the oil by my self from now on. Thanks!

My Car is Dodge Charger SXT '07. (My trusted mechanic told me that it was low oil pressure caused by counterfeit oil filter)