DHD 2011-2016 Duramax LML 9th Injector Plug – DHD 1-018-342


Product Highlights:

This plug is used to block the non-utilized fuel return loop specific to the CP4.2, after converting a 2012-2016 LML to a CP3. A CP3 does not support this additional return plumbing. Not sealing this portion of the return off may result in a return fuel leak, hard starting or poor performance.