I have a 97 a4 1.8t. Last year I was having random misfirings, while the car was shaking violently. Replaced the ICM. Problem solved. This year, car was shaking violently again, but this time only p0302. I had spare coils so I replaced all of them. Problem not solved. I then thought maybe the ICM was bad again. I replaced it with one from a local auto parts store. Problem not solved. Then thought maybe the replacement was bad, so I bought another ICM from a different store. Still not solved. Also I replaaced all the spark plugs as well and still nothing. Everything I read for p0302 is ICM, ICM ICM. But I am thinking either injectors or wiring. Please help!

 

Could easily be a fuel injector.. Try swapping the cylinder 2 injector to another cylinder and see if the problem moves.. If its the injector you might be able to clean it by soaking it in seafoam for a hour or so. Or you might just replace it..

 

Ok, so I changed the spark plugs still rumbling and CEL was still on. Reset the CEL and it was running much smoother, but CEL still on. Finally took it to my mechanic to run the compression and we he started it up engine ran smooth as silk. He reset the CEL and it still hasn't come on.