Originally Posted by LakevilleSSEi
Mine idles rough once it'* about half way to op temp, and it'* probably worse in gear.
It all feels the same anymore....getting sick of it.
My '92 sse */c is basically like that too, and I've never found the cause.
It has plenty of power, starts right up, never stalls, gets decent fuel economy, and has no error codes, but usually idles a bit rough. The RPMs are steady at idle.
Mine, though, will idle rough on one day and idle much smoother the next day...same time of day, same ambient temperature, same distance traveled, same driver, same driving style, same traffic conditions. And sometimes it'll idle pretty smoothly as I come to a stop, and for the first couple of seconds after the stop, but the idle will slowly get more rough the longer it idles at a stop. The RPMs don't vary when that happens, and the boost gage reading is pretty steady. Kinda suggests a vacuum leak or sensor problem, but I've yet to find it!
I'm beginning to wonder if maybe part of the problem is the gas. I always use 91octane (this is the highest premium octane I've seen in my area), but California reportedly reformulates the gas at different times of the year.