During the winter here in northern Ohio I have been experiencing a reduced power mode in my Chevy diesel powered truck. It has happened repeatedly, almost daily, and on Friday, Mar 20th, while driving on the freeway the truck unexpectedly went into this reduced power mode twice and dropped from 65 mph to less than 40 mph, almost causing a crash because of the sudden deceleration in one instance. I have been to the dealership twice now over this issue, in both cases they said it was my aftermarket air intake product and it's supposed fouling of a key engine sensor, the maf sensor. They blamed oil from the air filter fouling the sensor, and yet the air filter was there and there was no sign of oil seepage or fouling of the sensor. Since then I have, at my expense, replaced the air intake system back to factory and the maf sensor, and all that was before Friday when I almost got hit by a semitruck. I have researched the internet, consulted with two aftermarket air intake manufacturers and have determined that this issue is not what has been blamed to date but something else faulty on my truck. Either in the wiring harness affecting sensor output or a different sensor that works in conjunction with the one sensor that the dtc says is at fault. There has been issued tsb's on this engine family relating to my issue, GMC is aware that there exists an issue, and yet I have to pay out of pocket for repairs and parts and labor for something that should have been resolved the first time under warranty. The dtc is P0102, maf sensor low input, the sensor I replaced looks identical to the one I put in, no signs of fouling. I even at one point purchased a maf sensor cleaner made by crc, used it according to directions and still got the dtc, the reduced power mode and a check engine light. The truck will resume normal operating after 15 to 20 minutes, but then will fault out again soon after or on the next restart. No issue last winter, even w/ the aftermarket air system.

- Lakewood, OH, USA