Sorry to bring up this subject again, but I have the same symptoms(rough idle from idle to around 2200 rpm, engine light flashing). However, when I am on the highway from 2500 rpm and up, the engine seems fine and the CEL goes off. After reading an old thread, I decided to check the coilpacks and plugs. The no 1 and 2 cylinders had oil on the plugs. However, after cleaning them, I wanted to test the coilpacks individually so I removed the plugs one at a time and put them back in the coilpacks and started the engine while grounding out the plug. one by one, all the plugs seemed to be firing. My question is, if a coilpack is defective, would its plug not fire at all? Also, there is a ticking sound that seems to be coming from the passenger side of the engine, almost as if something was shorting out, almost like a bad spark plug wire on an older engine. I can change the plugs and packs, but could it be a bad injector? As I stated before, the car runs fine over 2500 rpm. Any comments?

 

I've seen this before, is your coil pack harness. Trace back the harness and you should see physical damage to the insulation on theharness itself causing your rough idle at certain RPMs. ECS has a replacement harness, and I believe urotuning does too.

 

It ended up being a vacuum leak, I changed the plastic hose at the back of the valve cover and the PCV valve. It fixed the bad idle and the engine now runs fine, but the CEL is still on. Does it have to be reset, or is their still something wrong? I read on another thread that disconnecting the battery and ECU for ten minutes would reset the ECU and possibly get rid of the CEL. Any comments?

 

I don't know if that would actally work on our computers, the best way to reset it is to clear the codes, also while you're at it read them and see what the code was, it should have been something like P0170 or something like that. I know a way to discharge old codes but it might not work for you. Disconnect the battery, positive and negative, then touch the negative and positive cable together, with the battery disconnected, hold them for about 5 seconds, then reconnect your battery and see the results.

 

It worked! You da man, Dan! Thanks, Marty

 

Hopefully your light doesn't come back, don't do that too often though.