Engine Controls - O2 Sensor Contamination Prevention

Section Title: Engine

TSB No.: TS 10 11307

Division: Automotive

Category: Technical

SUBJECT:
ENGINE OIL FILTER CHANGE PRECAUTIONS; 02 SENSOR CONTAMINATION POSSIBLE CAUSE OF DTCS P0137 AND/OR P0420

MODEL(S):
AERIO (RH420 / RH423)

YEAR:
2002-2007

CONDITION:

When removing the engine oil filter it is possible for engine oil to drip on the downstream 02 sensor. This oil can contaminate the 02 sensor internally which will reduce the 02 sensor performance and possibly set a DTC P0137 02 Sensor Circuit Low Voltage / High Voltage (Sensor-2 Bank-1) (EVAP Leak Check Model) and/or P0420 Catalyst System Efficiency Below Threshold (Bank-/)

CAUSE: N/A

CORRECTION:





To prevent 02 sensor contamination use a shop towel folded over to cover the 02 sensor. Be sure to remove the shop towel before running the engine.

WARNING:
Allow the engine to cool for a few minutes before servicing engine oil and filter. The engine oil can be over 200°F.





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