Car bucks after driving 30 miles. Engine light finally comes on then stops bucking. Light goes off, bucking again. Code number 12 32 55. Had tranny rebuilt last year. Confused on whether a tranny prob

Here is my full story since I could not fit it above. My 1995 Grand Voyager was riding fine for about 30 miles until it started to buck. RPM's went between 1 and 2, to 3 and 4, then back to 1 and 2 and then rev back to 3 and 4. Very erratic. No check engine light just yet. The next day it did the same thing, bucking, etc. When I got home I let the car sit over night and then started it again to go to work. At first it started to buck just like before, but then after about 5 minutes, it stopped bucking. So now I'm riding along when the check engine light suddenly comes on and doesn't go off until I got to my destination and shut the car. Drove the car back home and now the engine light is off. Once again, 10 minutes later, engine light comes back on. The strange thing is that the car did not buck at all while the engine light was on. I pulled the codes when I got home and got 12 32 55. I looked up what this means and it says that it's the EGR solenoid circuit open or short. Could this be the cause of the bucking? I ask this because I had the transmission rebuilt last year and at first I thought it might be that, but now I don't know since it doesn't buck when the engine light is on. Last night I drive the car again. This time the engine light did not come on and sure enough, the car started bucking once again. I'm very confused on what this could be. Any answer would be greatly appreciated.

Here is an article on a bad EGR: An EGR valve works by recirculating used exhaust gases into your engine. These gases contain unburned fuel but very little oxygen, and they're very hot. A hot intake charge carries less oxygen, so a working EGR system effectively makes your engine act smaller than it really is. In terms of driving, an EGR valve that's stuck open will cause a noticeable drop in horsepower at the very least. Along with that may come detonation -- "knock" or "ping" -- under hard acceleration, and the attendant cylinder misfires. The engine will also see an open EGR valve as a massive vacuum leak, so expect hard starting and a very rough idle. An EGR stuck closed or clogged with carbon won't exhibit many symptoms, since engines don't technically need them to run. But expect a very noticeable drop in fuel economy, a noticeable gasoline smell from the exhaust pipe, a very hot catalytic converter, or all of the above. All modern vehicles monitor the EGR system, so any fault with the system should trigger a check-engine light. You'll get one anyway if the engine ends up detonating, misfiring or running rich; all of these will trigger diagnostic codes. But you should find EGR diagnostic codes along with them if the EGR is the source of the problem. I would say that you should replace your EGR. Does not sound like it's related to your transmission.

@Reelin68- Thank you so much for taking the time to answer. I also have some vacuum hoses that need to be changed. I had a smoke test done on them and the smoke does come through some fine cracks in the hoses in the location of the EGR. Would a vacuum leak cause the type of bucking that would feel something is wrong with the transmission? A mechanic had told me it could but now that I'm seeing this code, I don't know whether to go the route of having the EGR changed or try the hoses first and see if that works. They're both expensive propositions. I don't want to have the hoses changed and then still have the bucking problem and vice versa having the EGR changed and it's the hoses that are the culprit. Very confused.

Well from what I can get on the internet, the 32 means EGR circuit fault. Which means it's either stuck open or closed. If I were you I would just replace the vac lines and replace the EGR while it's in the shop. Otherwise you will have to bring it back and pay for more labor if you take the 50/50 chance that it's one or the other.

@Reelin68- Yes, I probably will have to go that route, but I hope it's not too expensive. Right now it's the only thing I have. I hate to sound dense here and I appreciate your patience by asking the same questions, but do you think that is the definite reason for the car bucking? Maybe it's causing the tranny to malfunction, making the RPM's go from 1 to 2 and then jump between 3 and 4 and then back down again over and over?

It's hard to tell. But since that's the only code that came up, I would say all your issues are related to the EGR. There are other things that will cause an engine to surge such as a bad MAP sensor. But that should have given a code if bad. I think the bucking you are experiencing is in fact a misfire. Your engine is skipping. Like if you've ever had a bad plug wire or cracked distributor cap in the rain.