why is my idle surging? i think its the iac
my idle is surging after the car warms all the way up. it surges from 1000 to 1500 and its really annoying. i think the idle air control valve needs cleaned or i need an o2 sensor! IDK ANYTHING about these cars ive never had an import or a v6 that i've worked on and im really confused! please help
also if this has anything to do with it, if i stay at a speed say 45 for a couple minutes the check engine light turns on and stays on until i turn the car off. then it goes away until i stay the same speed again next time im driving.