Posted: 12/29/14 02:26 PM
I have a 2004 40th Anniversary GT (reference MM&FF Oct 2014 "Reigning in the Horse"), and I have been dealing with a persistent high idle problem with the car. I'm at a loss on what to do next.
Whenever the car is under load, the idle will rise inbetween shifts instead of fall. This remains true whenever I come to a stop and the vehicle is in neutral. When the vehicle is stopped, the idle will hold, then suddenly plummet before stabilizing at a normal idle speed. I've put the stock T/B to help with troubleshooting, swapped the IAC, PCV and even ran a different MAF to see if it would make a difference. Nothing. The only thing that I haven't changed is the EGR, but at this point I'm burnt out with spending money pursuing this issue. I could use some sensible pointers here. Any help would be greatly appreciated.
The ECM isn't giving any codes as of this writing. I was getting a P02270 code for a lean O2 Sensor, but that was subsequent of an exhaust leak. I'm theorizing that the issue could be resulting from a fuel or EGR issue given the characteristics of this issue. But, as I said, I could really use some advice.