MASS AIR FLOW SENSOR CODES

Diesel World,

I own a '13 2500HD with a Duramax engine that I bought new. The truck now has about 50,000 miles on the odometer. I installed a Magnaflow Dpf-back exhaust system early on, and until recently was using an oiled-pleated cloth air filter. I've done no other modifications to the truck. I didn't need to; it pulled my rather large RV trailer with aplomb.

Recently, the truck has been setting DTC P0102, which indicates a problem with the Mass Air Flow sensor.

Operating conditions have been like this: With above freezing temps overnight, the truck starts and runs like it should. No Service Engine

Soon light, no “reduced power” mode, nothing. But, when overnight temperatures drop below freezing, the truck goes into this reduced power mode and the Service Engine Soon light comes on. If I let it idle until the engine temperature gauge begins its climb above 160, the lowest reading on the gauge, the truck exits the low power mode but the service engine light remains on. Of course, by the time I get it to the dealership, everything has warmed up and the problem has gone away - except that the truck's computer shows this trouble code in history. The dealership was quite happy to inspect my truck, read their computer, scratch their heads and be mystified as to what was happening. And, they were more than happy to charge me for time and labor.

Following that visit, the cool October overnight lows have been dipping well below freezing, so I am seeing the Service Engine light and limp mode nearly every morning.

The dealer techs suggested I reinstall my factory air filter, suspecting a fouled MAF sensor may have been caused by filter oil. So, with the computer codes cleared and paper air filter reinstalled, I waited for the next morning start. With the overnight temperatures again in the low 20's,