ok so my 1993 bonneville started shaking and its smells like gas fumes in the car, so i cant drive it cause i have a newborn baby.so i took it to the dealership, they said codes 53,54,55,42,66 came up. they said i needed a new cadiletic converter, so i went to a local muffler shop. they said it was glowing cause it was so hot and said that wasnt the problem.i called the dealership back and they said they cleaned the egr vavle but said maybe it needs to be replaced, well before i spend any money i wanted to get everyones opinion, the car drive great, only shake when ur at idle. and smells awful inside uld this be the egr valve ?
I have a 1996 Firebird with the same 3.8L V6 motor. I recently had to have the EGR valve replaced, as well. I am not sure- but I think that the EGR valve has to do with the emissions. It may not pass an emissions test if the EGR valve has been bypassed. If you have to have it replaced, it probably won't be that expensive. Good luck. EDIT: here is an explanation of what an EGR valve is, and what its function is, thank you to this gentleman named Shovelkicker for providing an answer elsewhere in 'answers.'
could be egr or fuel pressure regulator. while running pull vacuum line off of regulator if fuel is present its bad .
A catalytic converter will glows red hot when raw fuel is introduced directly into it. The dealer is incorrect in saying that there is a problem with the converter itself. The problem is stemming from either the fuel or ignition system which would allow unburned fuel to pass through to the converter. Some possibilities are improper ignition timing, fouled spark plugs, air pump failure, Even though the catalytic converter glowing red hot is not caused from a clog if the converter is operated too long at a high temperature, its substrate will melt and re-harden. This would in turn cause exhaust blockage. Fix the fuel problem first and if the engine is still running rough (without a red hot converter), then it will need to be replaced.
You most likely have a bad egr valve. The valve is stuck open, that is why the idle is so bad. In normal operation, the egr is never open at idle. The valve being open at idle causes the map sensor to misread the manifold vacuum. This make the computer dump extra fuel through the injectors. That make the catalytic converter overheat, because there is raw fuel going into it. You may have already ruined the converter, but you want to deal with the egr valve first, then see if the catalytic converter is bad.
Having the CC being cherry red is a bad sign- and I think that the muffler shop got that part wrong. If the smell is like rotten eggs, the converter is definitely bad. Going by the codes, they are all the fuel mixture- and I would think that the cause might be the starting problem with the CC (I'd fix the problem first, the CC might just be OK). A lean burn condition will set all the codes you are finding, except the 66 (A/C pressure sending unit). It is going to sound kind of funny, but I would start with the fuel filter (just change it, they are cheap but can be a pain) and after that I would pop can the EGR to lock it out and see if the problem goes away- don't leave it like this, the thing is needed for the engine to run properly: Take the EGR off the engine- two 1/2 inch bolts on either side. Cut the ends off a pop can and cut it to fit the EGR and the bolt holes, and put it in between the manifold and the EGR and bolt everything back up. If the problem goes away, it is the EGR system back feeding exhaust into the intake at too low of RPM's. You still might find that the convertor is bad- that much heat melts the guts of the thing and creates back pressure that the engine cannot handle- just try the other two first just in case, the convertor is expensive.
