Hi Guys,

I am new and don't really know much about cars but I am desperate for some answers. I bought a used Audi A6 2.8 Quattro on Saturday (124k miles). It drove great but the next morning it started misfiring.

These are the codes that came up.

P0300 Generic Random Misfire

P0351 Ignition coil A Primary/Secondary Circuit

P0352 Ignition coil B etc

P0353 Ignition coil C etc

P0303 cylinder 3 Misfire detected

P0305 cylinder 5 Misfire detected

P0430 Catalyst system efficiency below threshold (bank 2)

I brought it in to my mechanic and he has done pretty much everything he can think of. He said there is a pretty much brand new coil pack on it. Also he seemed confused that these were the codes since he said these are what you would see on a 2.7 and not the 2.8 since on the 2.8 the coil pack is one unit. I need some help! Could it be a catalytic converter that's messing it all up? I'm stumped.

 

First step is to clear the codes and drive it. If a check light comes back on, scan it and see why. You didn't say anything about it driving poorly so there's a chance they're just old codes that weren't cleared after a repair in the past.

 

I brought it to the mechanic and he still cannot figure it out. It runs very poorly. It misfires when idling and as soon as you try to give it any gas it chugs. My mechanic replaced the air intake gaskets on the two cylinders that were misfiring, flushed out the oil with a chemical and put new stuff in, and he repaired a few hoses that were bad. The coil pack is an aftermarket one that jumps above and below the ohms (sp?) levels which is why the CEL comes on. I have noticed that the engine smokes quite a bit and there is a burnt smell as soon as I step out of the car. I opened the oil cap and noticed there is smoke coming out of the engine itself and its not just a leaking liquid that is hitting something hot and burning off.The error codes continue to be the same (minus the catalyst system code).

It has new spark plugs and a new timing belt as well. Anyone have any ideas what it could be? I can't seem to find anyone online who has had a similar problem. It is not driveable and the CEL flashes intermittently when attempting to drive down the block. Error codes still come up the same even after clearing them multiple times.

Please help! I don't want to sink too much money into this thing just experimenting to see if the issue is resolved.

 

Hey, did you figure out the problem?