Mustang Air Charge Temperature Sensors send the air inlet temperature to the computer so it can make the correct adjustments for the outside weather conditions. When the sensor isn't working right, it can cause your car to have a rough or erratic idle. LMR has a complete listing of 86-93 and 94-04 Mustang air charge temp sensors. Replacing your worn out sensors will help reduce emissions and keep your Mustang running like it should.