Codes P0300 & P0641
Thank you in advance for your time and for any thoughts on what may be causing my problem.
Car: 2008 G6
Background: On Monday I went to start my car in the morning and the check engine light came on, the traction control light and the car went into low power mode. I believe I turned the car off and restarted it, but, still the same issue. I drove to work in lower power mode. Either driving home from work or the next morning, I still had the check engine light on, but, no low power or traction control light.
I went into the dealer on Wednesday and by that time the check engine light had gone off. He read the error codes and they were P0300 (engine misfire) and P0641 5 volt Reference 1 circuit.
He said it could be a number of things and my best bet would be to bring it in, when it is still in low power mode, if it does it again. Sure enough when I went to pick up my car, he used the remote start to get it ready for me and show it off, I got in, never even looked at the dash, and when I looked down, a mile down the road, the check engine light was on!!!! He assured me that he had cleared the codes and drove it for 25 miles, with no issue.
It probably could be a bunch of things, but, do you have any recommendations, on where to start (probably cheapest to most expensive). I will go fill up with 93 octane and put some fuel injector cleaner in, but, other ideas would be very much appreciated. Sadly I am not very car savvy and don't want to get bent over by the dealer.