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P0420 Diagnostic Trouble Code Discussion for July 2004

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2000 Nissan Maxima GLE 3.0L MIL Lamp on VIN: JN1CA31DXY
P0420: Catalyst Efficiency Below Normal (Bank 1). ... a costomers Maxima with code P0420 - Catalyst low bank 1. I checked for vaccum leaks with the smoke machine, found none. Replaced dirty air filter, checked plugs and cleaned throttle housing. The ST & LT fuel trims on B1 and B2 are around 0.0 +/- 2 or ...
July 15, 2004
1997 Pontiac Firebird 3.8L MIL Lamp on VIN: 2G2FS22K2V
P0420: Catalyst System Low Efficiency (Bank 1). customer brought car to us with check engine light on and found dtc po420 catalyst efficiency low bank 1 looked at all parameters and look good cleared the code and let customer drive the car a few weeks later the car came back with light on again same dtc so ...
July 20, 2004
1999 Volvo V70 2.4L MIL Lamp on VIN: YV1LW55A4X
P0420: Catalyst Effeciency low Bank 1. I believe that I may have a wiring problem? Any suggestions, fixes or help would be most appreciated.
July 22, 2004