Put a scan on my new 385 LT1 and it said the MAF circut. I have an SES light on as well. I went to clear it, later it came back on. I took it around the corner and got on it and the car cut in and out under load with the SES light going off and the LOW TRAC light coming on. Question? In my tune I asked for my MAF to read descreened. THe MAF that I have was off a donor car and the screen is still in it. Could it be throughing a code because it needs to be descreened?
Chris

 

The minor differences in calibration between a screened and unscreened MAF would not cause a code.

It would help if you included the year of your car (or at least the PCM), and the specific code you are getting. There are certain years that have problems with the MAF wiring, and OBD-II has more than one MAF code. Without all the info, you're making it more difficult for people to help you.

 

Fred. ITs a 94 Camaro. I scanned it with a mac tools scanner. And it didnt give any specific number codes. I selected the option check troublecodes. ANd it read MAF CIRCUIT. Hope this helps.
CHris

 

There only one code in the OBD-I cars. DTC 48 indicates there is an MAF circuit problem.

With the key on, engine off, probe the voltage between the pink wire and the black/white wire. You should see 12V. Examine the harness connector for damaged pins. Make sure the MAF sensor is flowing in the correct direction.

With the engine running, if your multi-meter has a frequency counter, look for values in the range of 2,400-2,800Hz. Measured between the yellow signal wire and the black/white wire. 9,200-9,800Hz at WOT/max rpm. If you have a scanner that can read the MAF flow in grams/second, look for values in the range of 6-10gps at idle, and upwards of 300 gps at WOT/max rpm (a stock engine might only be flowing 240 gps under WOT/max RPM).

 

You may also want to check the wiring and plug going to the MAF. The plug went bad on my car and had to order and new plug/pigtail. From what I hear it’s not an uncommon thing to go bad on our cars. I would hit a bump and my car would stumble or nose over, then pick back up. With my car idling in the driveway, I would touch the MAF plug and the car would die. I soldering in a new plug/pigtail and all has been well.



Nick