P0420 Diagnostic Trouble Code Discussion for March 2022
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2008 Cadillac Escalade ESV 6.2L MIL Lamp on VIN: 1GYFK66808 P0420: Catalyst system low efficiency bank 1. ... Vehicle came for check engine light, no drive-ability issues. Codes stored, P0420 - Cat efficiency B1, P0442 - EVAP small leak, P2271 - HO2S B1S2 stuck rich, P0138 - HO2S B1S2 signal circuit high voltage, P0506 - Idle speed low, P1133 - HO2S insufficie... |
March 28, 2022 |
