First check your tv cable to see if it is hanging up(assuming it is the 03 in your sig). Have someone floor it while you are underneath and see if the tv cable returns all the way. next step if would be to put it on a scanner to check out the gov solenoid. Your govenor solenoid pressure should gradually increase with speed to about 130 psi when it shifts to fourth. If it is not a smooth increase, hangs at a low pressure, or jumps around alot, you have a bad solenoid. I am on my 3rd one, they are crap no matter where you buy them.