Originally I was having an engine light come on and we put the scan tool to and found it was to do with my exhaust saying something about left rear bank I beleive. Now when ever I get to around 4150 rpms it doesnt want to go past that and it makes a weird tinking noise coming from what seems to be the front of the motor it seems as if I have a rev limiter, which I don't and it restricts my horsepower when i get up to this level. When I got the car (a few months ago) it didn't have any problem going all the way to the redline. If anyone knows anything about something like this please let me know.