Hey guys have a problem. Over the last few weeks I have been trying to figure out why my truck is running lean, so yesturday I went over all the mechanical systems, one of tests was a compression test. Compresson is in the mid 160's all 8 cylinders but all the spark plugs are carbon fouled and the passanger side looks like it is running hot. Also the plugs that are fouled had oil up the threads all the way to the base of the plug. What could cause this to happen and what would cause it only on one side. Thank you for your help.

 

Check your fuel trims. I fixed a truck that someone had worked on and they installed the wrong o2s. This caused a -100 or positive 100 trim on that bank.

 

I had the y pipe off a few months ago to fab up my my hot side for my turbo system. When I was loging some base runs my fuel trims were 25+ ( wideband is on the pass header ) I didn't realize they were different. I will check that tonight.