99 A6 with a mis
 

My wife's A6 2.8 30V has developed a bad miss.
The code was P0302 misfire on #2
So I replaced the catalyic converters yesterday because they were rattling, but that didn't help.
Replaced the fuel filter, that didn't help.
Replaced the spark plugs, maybe a bit smoother but still has the misfire.

Here is what it does. It starts great and runs very smooth on the choke cycle, but as it warms up it begins to misfire and it gradually gets worse. It will occasionally runs fine as it's being driven for very brief periods. It seems to all but totally stop at higher rpms. The exhaust smell is strong, not the rotten egg smell of being too rich, but maybe the hydrocarbons of being too lean??

It started about 2 weeks ago and has gotten bad quickly.

Any ideas? O2 sensors? I read that the ignition modules on A4's can and do go bad. Where is that on a A6?

Thanks in advance.

RE: 99 A6 with a mis
 

i would think it is a coil going bad or a plug wire.it really would not be restricted to #2 if it was a bad ignition module,and a burnt valve would be consistantly bad

RE: 99 A6 with a mis
 

Yeah, I picked up a used coil pack at a local place (Veedub), but it was really bad. It wouldn't start at all because it blew a timing fuse. I planned to try another one. The coils aren't individually replaceable right? Does it also contain the ignition module?
Thanks

RE: 99 A6 with a mis
 

sorry i havent had any issues with my coil pack so i'm not as familiar with it as i should be,seeing that it has t-bolts attaching each coil to the pack i would assume each can be replaced,and i did not feel any wires so i believe it is a pin and socket connection and you should be able to replace seperately. a calibrated ignition tester can check the coils if on car,maybe an auto parts store near you will have one to loan.the problem could also be a faulty fuel injector.

RE: 99 A6 with a mis
 

I had a trip to a local fuel injection shop on my short list to have them cleaned and checked. It could definately be a possibility.

RE: 99 A6 with a mis
 

Considering that each coil fires two cylinders i would suspect the wire more than the coil.