GM / Chevrolet / GMC 6.6L Duramax
Duramax fuel system repair
CP3/CP4 pump, supply and contamination diagnosis for the Duramax.
Why this matters on the 6.6L Duramax
The 2011–2016 LML uses a CP4.2 pump; failures can contaminate the whole system. Other generations use the CP3.
Symptoms owners notice
- Stall or no start
- Rail pressure codes
- Metal in filter
What we check
- Filter inspection
- Rail pressure
- Water separator
Repair work involved
- Pump and contamination repairs
Trucks with the 6.6L Duramax
Request a quote
Not the right topic? Back to the GM / Chevrolet / GMC 6.6L Duramax overview.