Idle issues

[carthisis123]

Hi I'm new to the forum and I've owned my 03 galant es i4 for about a year and and a half now. Bought it with 82000 miles on it and you could tell the original did not take care of it at all. I'm starting to have some pretty bad issues with the idle. I've put new coils and plugs and wires. I've also put new headers with upstream 02 sensor. Also put on a new maf. The reason I replaced every was because the car would sometimes not idle and other times would idle at Park on a cold start at around 2400 rpm but even after the car warmed up the idle wouldn't drop. When at a stop in drive the car would idle around 900-1200 rpm. I replaced all these things and the car ran like a champ. No issues whatsoever besides the check engine light due to the catless headers I bought. Not even when months later the car has started to idle horribly again. If I unplug the maf sensor while the car is running it dies. If I leave it unplugged for a while and come back and crank the car back up sometimes it will be fine for a couple days and the rough idle would start again. The headers I bought are the stainless obx racing ones and they are pretty things and they get screaming hot and I didn't wrap them. Could the headers be getting the maf sensor too hot. My car is completely stock.

[BigRedtheGinger]

Try getting some brake cleaner and spraying around the intake. You could have a vacuum leak somewhere. If there's a change in idle speed when you do that, that's where the leak is.

Sent from my Z981 using Tapatalk