The PAIR Block-Off Plate is a solution for sealing off the air injection system present in the following bikes: CRF300L/Rally, CRF250L/Rally, Rebel/CMX 300, CBR250R, CBR300R, and CB300R/F. This system injects fresh air into the exhaust port to burn off residual hydrocarbons in the catalyst. However, when an aftermarket exhaust system is a