have a 2006 CTSV, I have kooks long tubes, high flow cats, running ngk 7 spark plugs as I am tuned to run a 75 shot. Car has been on a trailer for about 2 weeks as I have just moved cross country. Went to drive car to gas station and started misfiring terribly bad, I have never had a problem before with the car. And it just started throwing a P0300 code. Pulled all the plugs and they don’t look too terrible and wires look fine. I am about to replace all of them. And every once in awhile I will mix a little bit of 110 with 93 gas. I know it’s scrabbled but any options would be awesome.

Run it empty and try fresh gas before you get too excited? Where from and to? Elevation and humidity can do things.