I have a 2000 gt and i have a check engine light that read IAT 2 intermitten. I have already replaced it once and it fixed the problem for a while, but it has happened again. I have a flash tuner and have the car tuned to a preset, but I dont know if that makes any difference.

 

What was the exact code you were getting? My guess is that you have a break or short in the wiring. However, start with the basics. Check the air filter to make sure it is clean-ish. Then check the sensor to make sure it is clean. If all that checks out, then start tracing the wiring harness between the sensor and the ECM to see if there are any breaks or shorts. Good luck...