I have a ’98 Cavalier Z24 with the 2.4L. I recently had the Mantapart competition big bore throttle body installed on my car (1780 C). I can really feel the performance increase from this modification. However, the car now has a very rough idle. I set the idle RPM’s to the lowest setting, but there is still a rough idle and the engine light is on. The idle RPM’s are still too high for this product at idle. I was wondering if there was any way to fix this problem to lower the RPM's at idle. If not I'm going to have to unfortunately remove the product from my car. The engine light code is: P 0507 Idle Control System. Thanks for your help!



-Marty

Idle air control motor may have a dirty pintle, pull it off and clean it real good with throttle body cleaner, and make sure the bore for it in the throttle body is free of foreign objects. Also COULD be a vacuum leak. Before you pull the IAC off, start the engine and then spray that cleaner toward various places around the throttle body, ie at the base where it mounts to the intake, around all the vacuum lines, so on and so forth. If the idle changes at some point, note where you were spraying and fix the vacuum leak there. This may sound like a duh, but also make sure all your vacuum lines and wiring connections to the throttle body are well attached.

Thanks for the advice! I'll check it out and see what I can do. I appreciate the help

-Marty