Stainless 9th Injector Return Plug w/ O-Ring.
block the non-utilized fuel return loop specific to the CP4.2, after converting a 2012-2016 LML to a CP3.
For 2012, 2013, 2014, 2015, 2016 GM 6.6L Duramax LML
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.
Replaces# 1-018-342