Everyone Read This
I will probably get fired today because all i have been doing is looking up this freakin idle prob--read this--it makes sense to me because I have looked high and low for someone to say this
Question: 2002 Chevy Cavalier mileage: 70,000. My car's idle is supposed to be 900 rpm. Instead it idles around 1500 rpm. Also, it is a manual transmission and when I shift around 4000 or higher, the engine rpm remains high instead of going lower during the shift. I have replaced the IAC. I also have access to a Snap-On scanner. No codes are present and everything looks good. The scanner has the ability to vary the idle, which it does, but the idle is exactly twice as much as the scanner is programming it to do. I have checked the wire connections between the IAC and the computer and they are good. I have also checked the TPS with the scanner and the voltage and throttle position is accurate. At this point, I am leaning towards a computer. Thanks for any advice.
Answer: This is a difficult problem to detect because the computer can not sense a malfunction, the vehicles computer system thinks everything is ok. In reality what is happening is the electrical component inside the MAF sensor becomes contaminated by air impurities. These containments imbed themselves to the electrical component that senses the air flow causing the sensor to be slightly off, but not enough to trigger the MIL (malfunction indicator lamp). Replace the MAF sensor with a new. NOTE: (Mass Air Flow MAF sensor or Air Intake Sensor AIS, depending on manufacturer. It does the same thing only with different names).