I have a 2001 Audi A4 1.8t with 116k miles on it. I recently had this same issue and read up on it back in September of 2011. I was receiving a check engine light and it read misfire. I don't remember what cylinders. Anyways I replaced the plugs and coil packs. I bought the coil packs from a local auto parts store as I don't live very close to an Audi dealer. It is now the end of April and I am encountering the same issue (misfire upon acceleration) but there is no check engine light. I have searched the forums and have only seen this issue accompanied with the CEL. What could this be? I am replacing the air filter today to see if this helps but I seriously doubt that this would cause the problem. Could the coil packs already be bad?

 

Yes they could be. You also could have a vacuum leak causing a problem.

 

I've experience misfires with no CEL. Ended up being a (massive) vac leak. Do you have a boost gauge?

 

No, I don't have a boost gauge. This happens only when I, for example, want to pass someone and I don't grab a lower gear to pass. Maybe it's a turbo issue?

 

Doubtful. When one of my coil packs was bad it would only happen under acceleration.

Scan for codes, see which cylinder is misfiring and swap the coil pack around. If the misfire follows the coil pack, that coil is bad. If the misfire is random, it is most likely the ICM.

I put my money on the ICM.

 

And get a boost gauge.

 

Also that.