I myslef rock an 850 but my friend has an s40 and wants to ask a question. She has an s40 turbo with a Heico tune and Heico exhaust. When she starts her car in the morning for work it will sometimes die when exiting the driveway. Also, at stoplights, the car will bounce around 1000 RPM (not stay at steady idle).

I know with the 850's, they are old, and a lot of times it is a dirty MAF sensor. Same problem with hers possibly?

Thanks,
Patrick

 

Try cleaning the MAF first.
And also you didn't mention what year car this was...

 

It is an '04