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P0420 Diagnostic Trouble Code Discussion for April 2005

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2001 Toyota RAV4 2.0L MIL Lamp on VIN: JTEGH20V11
P0420: Catalyst Efficiency Below Normal (Bank 1). No data for air/fuel ratio sensors. Post cat O2 sensors seem to sweep okay. Has anybody seen the Cat fail at this low of mileage. The inside of the cat looks to be in place and the O2 sensors themselves are normal looking, slightly brownish black with the post...
April 11, 2005
1996 Nissan Pathfinder LE 3.3L MIL Lamp on, P0420 VIN: JN8AR05Y0T
P0420: Catalyst Efficiency Below Normal (Bank 1). Does anyone know of any alternative solutions other than replacing the catalyst.
April 12, 2005
1998 BMW Z3 Roadster 1.9L Cuts out, Stall, MIL Lamp on VIN: 4USCH7325W
P0420: Catalyst efficency low bank 1. ... having driven it for a few weeks, discovered that it will stall many times when stopping or going slowly. She had the car towed to me from 120 miles away because she "trusts me" (go figure!) Anyway I checked for codes because MIL is on and I get P0...
April 16, 2005
1996 Toyota Tercel DX 1.5L MIL Lamp on VIN: JT2AC52L3T
P0420: Catalyst Efficiency Below Normal (Bank 1). Vehicle came in 7/2004 with PO420. Followed troubleshooting chart. Led me to r&r convertor. Vehicle returned a couple of months later with same code. Customer was advised to replace O2 sensor. Customer did not want to spend the money, so I would turn mil o...
April 18, 2005
1996 Chevrolet Corsica 3.1L Hesitation, Surge VIN: 1G1LD55M2T
P0420: Catalyst System Low Efficiency. This car is from a local used car dealer. I'm dealing with an idle surge shortly after start up. I've checked fuel pressure/volume and for a leaking regulator-all ok. Spark plugs are brand new Autolite double platnium. Wires are oem. I've been watching scan da...
April 22, 2005