Hello everyone, I have a 98 b4000 that idles high. It has code 1506, I started by replacing the IAC and cleared the code. The code has not come back yet, but it idles at 2000 rpm on start up and 1500 after that. Looking for some advice on what to look at next. Thanks, Kevin.

 

I would tap on the throttle position sensor(while its running) with something solid like a wrench or ratchet. if it does not clear up and you have some extra money just replace it and see what happens. just a thought