[:@]My check engine light has been coming on intermittently for a little while now, and when I took it to the mechanic, his scanner gave him an error saying that the engine was "Running rich on bank 2" what could cause this? I tend to believe this is true because when the light is on, you can smell gas in my exhaust and my truck just doesn't feel like it's making any horsepower.

I've already replaced my air filter thinking maybe it was dirty and "choking" the engine. That seemed to fix it for about a week.

I was also told it could be my fuel filter, but how could a dirty filter cause this?

The problem first appeared in cold weather... -35 Celsius or -26 F (I think) but has happened once or twice in milder weather, closer to the freezing mark.

Any imput is appreciated seeing as these might be one of those expensive "ghost" troubles.

 

Sorry for the slow response... Forum problems caused a lot of new posts to get missed.

If you are still in need of help, what was the specific code?

Was it P0175 - Fuel Trim System Rich Bank 2?