Q: What can be causing my car to run so badly? on 1999 Nissan Pathfinder

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
My car was running beautifully but it was time for some PM. I had a new timing belt put on and replaced everything in that area that was exposed. I was told that the cam on the drivers side had been 1 tooth off so they turned it. This caused the motor to miss badly so they adjusted the distributer to compensate. This entire time my check engine light is on and the car is running in limp mode. Now they are saying that the car runs bad because of a plugged fuel filter so they changed it. The car still runs very bad and the check engine light is still on. The shop is saying it has nothing to do with the work they did and will no longer help me.
(1) Answer
It sounds like you got the wrong kind of help. You should never leave a shop after having any sort of job performed and have a check engine light on or experience any of the drivability problems you have been. The fact that they could not address the check engine light is even more worrisome. If you have paid them any money, you should ask for it back.

You need a good shop with a good diagnostician. These guys have a good review on RepairPal: