Just like the subject...I cleaned the IAC last weekend and installed a K&N air filter last night. This afternoon, I am sitting at a stop light and the Check Engine Soon light comes on!?

The engine sounds like it is running better. I haven't driven enough miles to determine if I have better gas mileage. I will by the end of the day.

Following the CES light coming on, I got to my destination, sat there and let the car idle for a few minutes to see if I get it again, nothing, although it seemed to be idling high, around 1000 - 1100 RPMs.

What would cause problems when the car is in gear and I have the brake depressed for 30 - 120 seconds?

------------------
BlueCat
87 Fiero Sport Coupe
Resurrection started 06/2002

did you unplug the MAT sensor and not plug it back in?, uum.. how is your throttle responce? did you know a vacuum line off under pelenum?

------------------

Check for error codes.

Found a cracked vacuum line. Replace it and the car started and idled great! Then tonight I temporarily parked the car on the street so that I could move the other cars out of the way...when I went to start the Fiero back up...it started but stumbled and acted like it was going to die. But it didn't. Seems like all the things I am going are helping, but not ultimately fixing the problem.

Any suggestions?

Tmo, I am going to replace the vacuum line next to the one I replace tonight.

Check the engine codes see what comes up.