i changed my exhaust to two brother pipe sounds great but now my red light is on cluster and the f1 ??????

 

what year bike?

 

Did you also remove the exhaust servo cable and change the position of the servo pulley in the process? You can remove the cable without causing any fault light to appear but if you rotate that servo pulley from the home position it'll give you a fault light.

Rotate the pulley back to home position with the notch facing toward the rear of the bike.