Hello,

My 03 CTS has had a rough idle it's entire life. It currently idles at around 600 RPM. If I give it just a little gas (bring it to about 700 - 750 RPM), the rough idle goes completely away, along with the awful shimmying. Is there any way to adjust my idle either manually or by computer? I'd rather not deal with a less than helpful dealership at this point. Thanks in advance! :)

You'll have to program the PCM. I am not sure who can, but check with EFILive and HPTuners, they are your best bet. Bring a fat checkbook though....

BUT, for $75, talk to Jesse Bubb @ wait4meperformance.com and see what he can do. $75 and unlimited retunes. And he is VERY good, I sat down with him on my 96 Suburban and he is a WHIZ at knowing and understanding what is going on. Give him a call. http://wait4meperformance.com/ You'll be glad you did. He can do nearly ALL GM cars.