03 trailblazer 4.2 engine idle surge with ac compressor


#1

The ac condenser unit will click every 7 seconds followed by a 3 to 400 rpm surge for 5 seconds or so, drop rpm then repeat. Belt looks fine, no slipping, new plugs a month ago, newish air and gas filter, does it in neutral or drive, read many ideas from low or high freon, iac, throttle body cleaning, o2 sensor, any ideas to narrow it down? no codes thrown. Maybe coincidental but was discussing o2 upstream sensor recently on this board. The car experiences the same symptoms while driving.


#2

Talked with a mechanic bud, he said let the car warm up, turn it off, disconnect positive for 20 seconds to reset the brains. take it for a drive let it get warmed up and try it out. Seems to be working fine now. Thanks for looking, and ps plan on doing upstream 02 sensor this weekend.