trying to install a 65 mm bbk tb on my 98 cobra. took off neg bat cable for 30 min. to reset comp. installed tb w/ tps but after 2nd start up throttle is sticking and check engine light is on. also slight hesitation. i loosen up two screws on tps and throttle is smooth but check engine light is still on. instructions w/ bbk tb list a plastic/rubber ring but no ring was included w/ set. what am i doing wrong? help. rob.