My Check engine light comes on and I check the computer. I get an ECU Code 14, which is Idle control system Malfuction. I changed to IAC Valve but my CEL still comes on now and again and my car is still acting up. If my air conditioning is on my RPM goes up and down frequently also I have a large power loss If I stop at a stop light I either have to turn off the A/C and drive off then turn the A/C back on, or rev my RPM to like 3500 to barely move. anyone know what else it could be?

 

Does it surge all the time or just when you have the air on, if its all the time its mostlikly a vacum leak. The air con will naturally make your car alittle slugish but im not sure how severe your talking.

 

Check if you got air in the coolant lines as well