P0420 Diagnostic Trouble Code Discussion for April 2023
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2006 Cadillac DTS 4.6L MIL Lamp on, open loop VIN: 1G6KD57Y86 P0420: Catalyst System Low Efficiency (Bank 1). ... open loop, even when sitting at a lite. When it goes into an open loop, p0420 kicks in. When I snap the throttle, it goes into an open loop, then back to a closed loop. |
April 20, 2023 | |
| 2006 Cadillac DTS 4.6L MIL Lamp on, open loop VIN: 1G6KD57Y86 P0420: Catalyst System Low Efficiency (Bank 1). ... open loop, even when sitting at a lite. When it goes into an open loop, p0420 kicks in. When I snap the throttle, it goes into an open loop, then back to a closed loop. |
April 21, 2023 |
