Originally Posted by Takeda
If there is a hard failure with the MAF sensor (like an open, or out of tolerance element) the PCM with throw a code, and you will get a CEL.
If the MAF sensor element is contaminated with dirt & oil (very common using a K&N air filter) the MAF sensor will measure less air flow than is actually flowing and will throw a lean code.
I have the lean code and that could mean many different things. I have changed plugs, wires, O2 sensors, and Fuel filter. I have cleaned the MAF with CRC QD electrilcal cleaner. It gives me the rough idle and has stalled a couple of times. If I unplug the MAF it idles up and smooth. Plug it back in and it runs rough again. I am assuming the MAF is bad but at $140 i want to verify that this is the fault the PCM is picking up. Is there a way to test or verify this sensor is operating correctly?