When it's cold, it runs fine. As soon as it warms up, it starts running rough (like it's not running on all cylinders). It's rough at idle, and when driving. Sometimes, you can let off the accelerator, and it smooths out until you try to accelerate again. I thought it might be the fuel filter (I just bought it, and it still had the original fuel filter at 180k miles), so I changed it. My acceleration did improve, but it's still running rough. It started a few days ago while I was driving it to the store, and has been doing it ever since. Can anyone give me any ideas as to what the problem might be?

 

Okay, since I changed the fuel filter, it is accelerating better. However, it is still sputtering while driving, and idling really rough at a stop. It smooths out some when I put it in neutral while stopped.

 

sounds like it could be o2 related...

 

O2 WAS MY 1ST GUESS

 

Is the CEL on? Does it work? If it is on, what codes are being thrown? If you unplug the O2 sensor, does it still do it?