2011-2016 LML Duramax CP3 Conversion Kit

Trade the CP4.2 for a CP3

The factory CP4.2 pump on the LML is known for trouble: even a little fuel or water contamination can wreck its internals and send metal through the whole fuel system, which usually means new injectors, sensors and lines plus a tank cleaning.

Wehrli brought the first CP3 conversion kit to market in 2013. This version folds its earlier kits into one part number, improves compatibility with stock and lightly modified trucks, and needs no tuning when paired with a new Bosch OEM LBZ-style CP3 (sold separately).

Who it's for

LML owners who want to replace the CP4.2 with a proven CP3 setup.

Key specs (per Wehrli)

What's included

• Billet CP3 mounting plate, CNC machined and black anodized
• Pre-bent CP3 feed lines, usable with or without the factory fuel filter housing
• Stainless high-flow CP3 feed and return fittings
• Pre-formed feed and return lines
• 9th injector lines and billet fuel distribution block
• FCA / MPROP valve extension harness
• Low-pressure feed lines
• Installation hardware

Fitment notes

• Fits 2011-2016 Chevrolet Silverado / GMC Sierra 2500 HD and 3500 HD with the 6.6L LML Duramax.
• Supersedes WCF100711 and WCF100249.
• Sportsman and stroker CP3 pumps need tuning (per Wehrli).
• California: Wehrli does not ship this part to California.

Professional install available at Powertech Diesel, Idaho Falls — call 208-542-7793.