I took my 2010 Malibu in to diagnose an oil leak. It has a 2.4L ecotec with 116K miles on it. It was determined the leak was coming from the timing chain cover seal. Once the work started it was discovered that the plastic timing chain guide had busted and the chain, tensioner, and guide all needed to be replaced. The work was completed and I took it to get gas and after getting gas I got the check engine light. Code was P0010. I brought it back and the cam position actuators were replaced. Got it back again, drove it to, from, and to work and when I went to come back home on that second day the light came back on. Code was P0172 saying the fuel system was running too rich. Brought it back to them, and I was told they did a hard reset to the computer system. They continued to drive it for the next 3 days using up 3/4 of my tank in the process. They said all looked normal and no codes popped so I could pick it up. I got the car, put gas in, took it to the car wash, and ran it for a bit while I was vacuuming (it was cold out). Brought it home. It sat in the drive for a while, I started it and it sat for about 5 minutes and when I went to pull the car into the garage and the light was on AGAIN! I took it to check the code and it popped a P0172 again. I’ll be taking it back in again on Monday, but does anyone have any idea what the cause of this could be? They claimed it never came on while they had it. I’m losing my mind over here.