My car hunts at idle, between 450-750 rpm. It is much worse when the A/C is off, but it still does it slightly with the A/C on. It mainly happens after the engine has warmed up, as before then it idles at a higher rpm smoothly. Does anybody know what this might be? I have adjusted the idle control screw, and it seems to make no difference. Is it the O2 sensor, or does anybody have any other ideas? Thank you in advance for your help.

Best regards,
huge123

 

Have you changed your spark plugs, wires or distributor lately? usually this problem is from the plug wires, but check all three to make sure.

The O2 sensor will trigger the check engine light, but not cause an idle problem.

 

I changed my plugs not long ago. I will check to make sure the plugs, wires and distributor are all functioning correctly. I bet that is it. Thank you for your help, I really appreciate it.

Best regards,
huge123