Wonder if anyone can help me diagnose this problem on a manual 1.8L 2000 Protege.

Background:
I recently got my timing belt replaced. Very shortly after that, i was getting rough idling (CEL came on), and replaced the EGR valve.

Currently, I am noticing that while the car is is motion (any speed), and I push down on the clutch, the RPM doesn't return to idle speed (around 700rpm), but stays at around 1500rpm or so. However, when the car comes to a full stop, the rpm will drop back to the normal 700rpm. I know it didn't used to do this before. Anyone have a clue what's happening?

Thanks

 

I wonder if the IAT needs to be cleaned like it always does on the 2.0 (they are the same engine after all.. just different pistons/rods).. I haven't cleaned mine ever (you need a security torx bit to open it), and at over 90k miles I have a similar thing where the RPMs dip down when I come to a stop but never while rolling. At 5ish mph at the end of my street I'll just go to neutral a few seconds before hitting the brakes.. the RPMs sit kinda high, then dip down below normal idle and come back up. I keep thinking it's an issue with vacuum lines somewhere but haven't traced it down.

I'll try to do the IAT cleaning this weekend and let you know if it stops that problem for me.

 

Sounds like the exact same problem. Even when the car is rolling to a stop in neutral it stays high at about 1500rpm. Then when i come to a full stop it dips down to the normal 700rpm.

Be great to know if cleaning the IAT will fix this.

Thanks.