GM 94011618 Duramax Cold Start Valve O-Ring Test Port O-Ring

Its always best practice to replace this o-ring during test port replacement or removal. Use this o-ring in conjunction with our DHD fuel test port caps or the OE test port to ensure a perfect seal.

Test Port Cap 007-0227

Test Port Cap w/NPT Ports 007-0243

OE Test Port 12637722