Hi, I got a 2007 GT. The only major mods I know about on the car is the Airaid Intake and No Cat StraightPipe Exhaust with Corsa Tips.
My problem is that recently, my GT been having extremely loud and high RPM Cold starts which is unusual. When I bought the car back in January, the highest the RPM would get was 2.5k (which I believed is still high).
Now, my GT during a Cold start starts at 2,000 RPM, slowly drops to 1.800 then jumps instantly to about 4,000 RPM for a few seconds before finally dropping down to normal idle at below 1,000. Besides the Cold start, the car runs fine, no issues with performance at all. I used to have a 91 Octane Race Tune I got with the Bama Tune but I Switched to the 87 Octane tune today but it still does the same cold start.
I don't know much about cars when it comes to troubleshooting so if you know how I can fix this, can explain to me how and use easy to read terms.
+1 on cleaning throttle body. Should also should clean the MAF while your at it. I had starting and idle issue at one time and found they all went away once I cleaned the TB and MAF. Actually, since I have made cleaning the TB and MAF part of my oil change routine, I have never had an issue with starting and idling in years.