Hollwood001

I have a 2000 Chevy Tahoe with a 5.3 in it. Recently this engine took out the intake gasket so I took it apart and replaced it. While in there I replaced the Knock, TPS, and IIAC sensors/motor. While assembling I left the battery unhooked as to reset the system. I started it up and it has a high idle/idle decrease hesitation problem. It starts and idles at 1100 rpm and you hit the throttle and it races to 2000-2500 and then slowly declines to 1800 RPM. I though maybe I left something off and sprayed ether over the intake and any point I though may have a vacuum leak and couldn't find anything. At one point I was receiving a p0507 code which is excessive idle but then I erase the code and it will go away for a few start-ups but reappears. I started to unhook sensors to see if I could get a response. I unhooked the TPS, IAC, EGR, EVAP, MAP, and MAF sensors. The only ones that threw codes were the MAP and MAF sensors. I have driven the vehicle down the road to see if it just needed to complete a relearn mode and it doesn't help. Could it be a bad ECM seeing as how the other sensors didn't throw codes? Please Help.

Hollwood001

For those people that are struggling with this Problem I finally found my solution. I realized if it revs up and hangs up then it is a Idle problem, so I unplugged my IAC valve and pulled it out and extended it so the valve was 1/16 to 1/32 open and reinstalled it. Then I started it with the connector unplugged and my Tahoe idled like it should. So then I pulled the PCM and did a continuity test on the wires (79, 78, 77, 76 in the PCM plug) and found that one of my wires had a break in it which caused my issue. I replaced the wire and the issue was solved. For those who want to replace the wires and connectors look on rockauto they have the connectors u need at a reasonable price.