P0420 Diagnostic Trouble Code Discussion for August 2020
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2011 Chevrolet Malibu LS 2.4L Poor Idle Quality, Surge, Stall, MIL Lamp on VIN: 1G1ZA5EU8B P0420: Catalyst System Low Efficiency. ... front catalytic converter. Replaced with after market converter, both 02 sensors, and exhaust headers. Checked operation and OK. Came back with same code. Found bad front converter bad due to rear and front O2 sensor identical patterns. Removed conv... |
August 04, 2020 | |
| 2011 Chevrolet Malibu LS 2.4L Poor Idle Quality, Surge, Stall, MIL Lamp on VIN: 1G1ZA5EU8B P0420: Catalyst System Low Efficiency. ... front catalytic converter. Replaced with after market converter, both 02 sensors, and exhaust headers. Checked operation and OK. Came back with same code. Found bad front converter bad due to rear and front O2 sensor identical patterns. Removed conv... |
August 05, 2020 |
