P0420 Diagnostic Trouble Code Discussion for January 2004
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2000 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 1GCEC19T7X P0420: Catalyst System Low Efficiency (Bank 1). bank one sensor #2 moving from 775mv. to 100mv. put new 02 in same results. fresh tune up and injector cleaning . bank 2 sensor 2 stays at about 750mv. |
January 06, 2004 | |
| 1999 Toyota 4Runner Limited 3.4L MIL Lamp on VIN: JT3HN87R9X P0420: Catalyst Efficiency Below Normal (Bank 1). vehicle arrived with po 420 only 4 possibilities are 1-exhaust leak. 2-A/F sensor (air fuel on bank one). 3-Heated Oxygen sensor(bank one sensor 2). 4- Three-way catalytic converter. history on vehice is perfect maintenance by a very reputable repair facility.... |
January 09, 2004 | |
| 2000 Volvo S40 1.9L MIL Lamp on VIN: YV1VS2553Y P0420: Catayst Efficiency below Threshold. Thought maybe the air pump was not pumping enough oxygen to "light up" convertor, but for the life of me can't find an air pump on this car? Anybody know where its located? All other specs look good...oxygen sensor voltages crosscounting good... Has ... |
January 21, 2004 | |
| 2000 Pontiac Sunfire SE 2.2L Stall, MIL Lamp on VIN: 1G2JB124XY P0420: Catalyst System Low Efficiency. customer complaint of ses lamp coming on and at times car stalling and not restarting. vehicle towed in but started right up found freeze frame data records for po420 and data display readings of coolant sensor at (-40 deg), vehicle speed at (37 mph), maf at (... |
January 26, 2004 | |
| 2002 Nissan Altima 2.5L MIL Lamp on VIN: 1N4AL11D62 P0420: Catalyst Efficiency Below Normal (Bank 1). ... this? Car came in with the MIL illuminated, had a code P0420 (catalyst efficiency) stored. Looks like they look for too much oxygen sensor variation on the post cat O2 sensor. Watched O2 sensors on a scope on a road test, periodically the rear O2 would mim... |
January 31, 2004 |
