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P0420 Diagnostic Trouble Code Discussion for January 2007

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1997 Mazda Protege DX 1.5L Poor Idle Quality, Stall, MIL Lamp on VIN: JM1BC1414V
P0420: Catalyst Efficiency Below Normal (Bank 1). hello everyone, need some help w/this mazda. came into the shop as a rough idle & stall espically when warm. once @ operating temp idle hunts up & down between 300-800rpm (give or take)& most of the time stays running but sometimes stalls. when veh...
January 17, 2007
1998 Chevrolet Lumina 3.1L MIL Lamp on VIN: 2G1WL52M6W
P0420: Catalyst System Low Efficiency. This car came in with the MIL and P0420 on steady. I want to know if the cat needs to be replaced or not. I took the following readings with my scanner. @ idle the front O2 toggles from 100mv to 500mv, STFT 0% 128 BL, LTFT -26% 94 BL and the cat temp was 512 d...
January 19, 2007
1997 Lexus ES300 3.0L MIL Lamp on VIN: FT8BF22G3V
P0420: Catalyst Efficiency Below Normal (Bank 1). ... this car came to us because it failed mass emissions test for check engine light on and code p0420, above related repairs were done at their regular shop, they are a first time customer to my shop so i have no other history, my test results) converter fail...
January 19, 2007
2002 Toyota Sienna LE 3.0L MIL Lamp on VIN: 4T32F13C92
P0420: Catalyst Efficiency Below Normal (Bank 1). I'm looking for some help/clarification. I beleive The catalyst is worn out on this car. Rear O2's are too active, indicating a spent converter. However, Toyota has a TSB for this code which says, essentially, replace the ECM-no diagnosis, just replace. My fee...
January 25, 2007