How's it going? On Monday, I put on a new BBK 75mm throttle body and everything was great. Noticeable increase in power and all was fine. On Tuesday, I went to a muffler shop and had my 4 cats cut off and replaced with 2 Magnaflows. Exhaust system was very loud and gained a little more power. When I got home I noticed a part of the welding popped out and there was a pea size hole blowing exhaust air. Brought it back and he patched it up.

Today I was heading to work and the freeway was backed up for miles and miles. I got off the highway and a few minutes later my check engine light came on. I went to first Autozone I came across and he pulled a P1506 code. He said he couldn't find it in his book and that I had to go to a dealer. Came on here and found that it is a "Idle Air Control Over Speed Error." Anyone know what the problem might be. I've read that replacing the IAC sensor could do the trick. I might pick one up on the way home at Autozone. I just hope it's not a vaccuum leak or something a bit more complicated. Any help would great. Thanks.

 

Check your other post and read about adjusting the TPS and adjusting the throttle stop.

 

Thanks lxman. On the way home, I stopped by an Autozone and the guy suggested the same thing. I bought an IAC valve anyway since it was really dirty the last time I looked at it. About 5 minutes after I left Autozone the check engine light went off. I thought that was funny.

Anyway, I did think that the 900 rpms at park was a bit high, and it hasn't gone down at all. I'm going to adjust the stop screw and see if I can figure out how to test the TPS. I might just replace it also. Should I adjust the stop screw while the engine is running until it goes down to 700 or should I do it the way you suggested first? Thanks again.

 

Do it with the engine off.

 

Alright did with you said and after I started her up she eventually went down to 750 in park and 700 in gear. Thanks again.

 

No problem, glad to help

 

high idle ( 1100 rpm ) after getting P1506 code. i do have K and N and magnaflow cat-back on the truck. should i adjust the throtle stop screw or TPS ? all my hoses seem good. this is a 2001 5.4 4x4 exp. with 97k thanks.