i recently installed a pacesetter header and 2.5 inch exhaust on my cobalt now when i start it and run it it has high idle even after i drive it awhile it wasn't like that before why could it be doing it ? how do i slow it down ? everything is hooked up right the check engine light is not on so i don't know

 

get a pcm calibration

 

Hmm not to sure as my 2.4 never did that when I got my header and exhaust. You could try and reset the ecm by disconecting the battery. If that doesn't work I suggest getting your car tuned by hp or trifecta as you want to do this soon anyway as it will make a huge difference to your car with your new mods.

 

iam wondering if i have a vacuum leak or something going on ial guess ial haft to spray it down to see if it changes how it runs

 

Either that or ure egr valve is not plugged in. .......... I dunno id have to look at it mysef

 

well when i started my car today it wont idle any less the 1500-1800 so this morning i went to the parts store and bought some auto-light spark plugs and guess what it made a difference now it idles around 600 i was running them green E3 spark plugs who could of known plugs made a difference so ya