Hi, I'm driving a 2000 GMC 1-ton with a 7.4 liter engine and recently took it into a shop because there was a gasoline smell coming from the exhaust.
They hooked up a computer and said the only code that came back bad was an O2 sensor so they replaced that and told me it was fixed.
But I still smell heavy gas fumes after the engine runs for over 15 mins. When they look at it, the engine is cold and there is no gas smell. After I drive a while I cant leave the windows open or I get choked out by the fumes.
A friend told me it might need an Air / Fuel Mixture adjustment. What kind of shop can do this? Am I stuck taking it to a dealer or are there shops that specialize in this type of service?
Thanks for any help you can provide. BS