2013 GMC Sierra 2500 HD
Mileage
147,682
Service Date
5/20/2025
Services Performed
- No check engine light on at this time. Checked codes: P0420 catalyst system low efficiency, P11CB nox sensor 1 performance signal high. No freeze frame data available for codes. Cleared all codes and monitored live data info for Nox sensor. Road tested to operational temperatures. Attempted to perform regeneration, failed due to DPF differential pressure, soot load at 0. Distance since last DPF regeneration was 34.18 miles ago. Rechecked for codes after road test, none found. Due to history of codes: recommend replacing 9th injector (Indirect injector).
- Removed intake air tube, top of air box, inner fender lines, and 9th injector. Disconnected electrical connectors and bracket bolt from fuel line. Installed new injector and reinstalled all removed parts. Cleared codes and road tested to operational temperatures, no codes returned.
Matthew W. gave our service a 5 star review on 5/20/2025