2000 dodge ram 2500 5.9 360 gas, with high idle at about 1500 to 1800 rpm. codes where that the p0505 what is the iac. so replaced the iac, tps, map, and upstream o2 1 of bank 1 o2. reset the computer and nothing. cleaned the iac, and tps spots somewhat with carb and choke cleaner. and no change. looking for advice

 

could be a vac. leak causing the high idle. do you hear any hissing? like possibly around the throttle body gasket ? you can test for leaks using some carb cleaner and shoot it around the gasket areas and see if it changes the idle, if it does then u found your leak. just a thought.

 

Iac is idle air control valve its on the back of tb. You could also clean the iat. Or thoroughly check the iac wires there maybe be a short between it and the pcm