Whenever i give about 50% to 75% throttle in 3-6 gear, i get this violent shake and alot of hesitation and vibration...but after about 3000 rpm it kinda subsides, but not really.....now, this problem only started after i did my header install, and has gotten worse as time progresses....so, im thinking burnt wires. I checked the drivers side real fast and they didnt look too good...not all the way burned through, but im sure there are spots i didnt see...... any ideas? im hoping its something this simple since im doing the OVC kit anyways....any ideas?

 

Sounds like your transmission is vibrating your y pipe. My car did this until I had the y pipe welded to the cat back.

 

right now the y-pipe is welded to the CAT