I just purchased a sct xcalibrator. I hooked up the tuner to my car did what it said and selected the octane i wanted then I scrolled down and left everything alone except for the speed limiter. It download then i unpluged it turned the car on and it wouldn't start so i reinstalled the stock tune. So do i have to messes with the air ratio etc. Because i thought you just select the octane and do whatever else you wanted and then it would be done. So any input would be great.
2006 mustang v6
hutch
2006 mustang v6
hutch
