Check engine light intermittently comes on after engine is warmed up. This is accompanied by the engine stumbling, running rough, or hesitating. Mine was blowing black smoke from the exhaust because the computer was running the engine too rich. Pinging can also be a symptom of a bad MAF sensor.
If your truck is doing this, try unplugging the wiring harness from the MAF sensor, which is located in line with the air intake. If it runs better with the MAF unplugged, it is probably bad. The Check Engine light will definitely come on with the sensor unplugged. The sensor can also just be dirty - you can remove the sensor with a security TORX bit and use MAF sensor cleaner spray to clean it. I have replaced mine twice over 20 years of owning the truck, and the symptoms were a little different each time.
The second time I replaced it, I actually took the truck to a mechanic because it was running so bad. They wanted to change the plugs and wires and go from there. I declined and that's when I tried unplugging the MAF. You would have thought a mechanic would know to try that. The plugs did need changing, but I did them myself and I did not really notice much difference vs. running on 20 year old plugs (with a new MAF sensor).
Check engine light intermittently comes on after engine is warmed up. This is accompanied by the engine stumbling, running rough, or hesitating. Mine was blowing black smoke from the exhaust because the computer was running the engine too rich. Pinging can also be a symptom of a bad MAF sensor.
If your truck is doing this, try unplugging the wiring harness from the MAF sensor, which is located in line with the air intake. If it runs better with the MAF unplugged, it is probably bad. The Check Engine light will definitely come on with the sensor unplugged. The sensor can also just be dirty - you can remove the sensor with a security TORX bit and use MAF sensor cleaner spray to clean it. I have replaced mine twice over 20 years of owning the truck, and the symptoms were a little different each time.
The second time I replaced it, I actually took the truck to a mechanic because it was running so bad. They wanted to change the plugs and wires and go from there. I declined and that's when I tried unplugging the MAF. You would have thought a mechanic would know to try that. The plugs did need changing, but I did them myself and I did not really notice much difference vs. running on 20 year old plugs (with a new MAF sensor).
- msubully82, Madison, AL, US