P0420 Diagnostic Trouble Code Discussion for September 2017
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2002 Nissan Sentra CA 1.8L MIL Lamp on VIN: 3N1CB51D42 P0420: Catalyst Efficiency Below Normal. This vehicle came in with CEL on and it wont pass state inspection because light is on. Car was at another shop that replaced cat & O2 sensor. This engine has two upstream sensors & two downstream sensors. One upstream & one downstream with blue co... |
September 22, 2017 |
