I've been having a rough idle in this car for quite some time now. I also can't get the random cylinder misfire CEL to go away either. The past time I checked for codes I also had one for the EGR, I forget the number though.

Here are some things I've done to no avail:

- smoke test for boost/exhaust leaks - good to go
- sparktech cop system and new plugs (needed it anyways)
- new fuel pump and filter (needed it anyways)
- erased the codes but they came back
- added some injector cleaner to my fuel


I did a compression test last summer and it came up fine....not sure where else to look. Here is a video of the idle ....



As you can see the rpms bounce up and down and then it just goes completely lean. You can't hear it but the car will kinda skip a beat as it idles.

 

Check your IAC. Its right under the throttle body and has 3 small screws u need to take out. Clean it off and did u get a tune after the cop set up?

 

I tried cleaning the sensors as well. I'll look at them again....and no, I didn't get a tune after the COP but this has been an issue even before it.


Also forgot to mention that while cruising down the highway the car will randomly start stuttering and the wideband will go completely lean.

 

The fact that you got a CEL for EGR says something to me. I was getting that code and eventually found I had a broken vacuum hose going to the egr solenoid under the intake manifold. Once I fixed that hose it fixed the code and helped the idle.

Cleaning the MAF sensor helped my idle a ton (it did look really dirty)

 

I'll try cleaning things again and see if that helps. This idle is getting pretty damn annoying and I don't want to start swapping all these parts and not have it be fixed.