P0420 Diagnostic Trouble Code Discussion for January 2025
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2013 Buick Verano 2.4L MIL Lamp on VIN: 1G4PS5SK7D P0420: Catalyst low efficiency. This is a friends car. Came in with above trouble codes. I fixed the P013 by diagnosing and replacing the solenoid. Tested O2 circuit. Led me to bad O2 sensor shorted to power. Replaced to O2 sensor and that brought the voltage down below 1. Running around... |
January 22, 2025 |
