2011 GMC Sierra
Mileage
164,970
Service Date
5/28/2025
Services Performed
- Scanned for diagnostic trouble codes, found three: P0522 – Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low P20EE – NOx Catalyst Efficiency Below Threshold P207E – Incorrect Reductant Composition Need to start by removing the DEF injector from the exhaust system and testing quality, quantity, and pressure. However, nuts on DEF injector look very rusted. Its a cause for concern as they could break. Need permission to continue. Was able to remove DEF injector. Performed quality and quantity test. DEF fluid is milky in cooler and has poor PH concentration. Will need DEF system drain, refilled with good DEF, and a regeneration and system reset preformed. Poor DEF quality has damaged the rear NOx sensor and will need to be replaced.
- REMOVED AND REPLACED POSITION 2 NOX SENSOR
- DRAINED AND CLEANED OUT DEF TANK. REFILL WITH FRESH DEF
- FORCED REGENERATION & REDUCTANT QUANTITY RESET PROCEDURE – Perform
GARY F. gave our service a 5 star review on 5/31/2025
