My 03 4.6 is having idle issues, I have already checked the 90°elbow and it's fine, next step is throttle position sensor and iac valve. Before I go buy them I would like to try them out to see if that's my actual problem. I have a buddy with a 97 4.6 that runs great , I would like to put his tps and iac in my truck and see if it fixes the problem then put them back on his truck and go from there. My only concern is will it in any way mess up his parts or his vehicle, I don't want to do any harm to his stuff if he's helping me out

 

Try the IAC valve first, it shouldn't hurt the parts.

 

Parts are different from 97 to 03.