The GM-46091 Charge Air Cooler Tester has been used to test induction systems on vehicles equipped with a 6.6L Duramax diesel engine since 2001. Various adapters to this base Tester have been developed as vehicle and powertrain changes have occurred. For the 2017 model year the new engine RPO L5P has exhaust pipe changes that require a new test adapter. EN-46091-10A is used with GM-46091-25A to cap the exhaust system so that the engine and induction system can be pressurized and inspected for air leaks.