I have a 2003 3.2 CTS and I started getting an error " service engine idle control" What is this? Where is it located? And how do I replace it? And how much does it cost? The engine idles slightly higher due to this and I notice it runs a little different. Any ideas?
Thank you

 

there should be a code , u need to pull it
but what it is telling u is the idle is not stable could have air leak or something
should be setting a high idle i am guessing p0506 or p0507
u may just need to clean the throttle body may be stuck open due to carbon build up