There is nothing whatsoever in changing shifters that would cause your traction control to do this. Pull the bezel and check the wires for loose connections or a plug that is unplugged.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.