Took truck in to have valve cover replaced because I lack the tools. Well upon picking the vehicle up, I got a check engine light, but the shop was already closed and I don't live to far away so I drove it home cause I have the tools to diagnosis that. Upon reading the code it was engine running lean. I cleared the code and proceeded to inspect the engine bay. I first noticed that parts were just left in the engine bay. One happened to be the PVC tube for the valve cover to the intake. So I replaced that. While doing that I found that a plastic body pin had been used to fill a hole in the valve cover were a wire loom hold was supposed to be. I also found that another wire loom hold down had been broken and not replaced. After removing the body pin I knew it belonged to the inner fender over the driver side tire cause that is one of the places you had to use to access the intake manifold. Upon inspection of this I found that body pins were missing and some had been placed in the wrong spots. To top it off I saw were the mechanic must have missed a body pin but instead of removing it he ripped the liner out of the wheel well. After correcting all the mistakes I could see, I haven't had the check engine light light up again. They did do a good job replacing the valve cover but defiantly lacked attention to detail when removing parts and putting them back on.