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P0420 Diagnostic Trouble Code Discussion for September 2011

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1999 Dodge Ram 1500 Truck 5.9L Poor Idle Quality, Misfire VIN: 3B7HF13Z0X
P0420: Catalyst Efficiency Below Normal (Bank 1). ... on and customer requested repairs be made in order to pass DEQ. Code came back as P0420: CAT Efficiency low. Read data stream while analysing emmisions; Both Pre CAT and Post CAT O2 sensors mimick each other. Readings are around 0.08 - 0.12V. Exhaust HC's ...
September 14, 2011
2001 Nissan Sentra XE 1.8L Cuts out VIN: 3N1CB51D21
P0420: Catalyst Efficiency Below Normal. Car runs great when started cold until driven for about 5-15 miles. Then idles fine and runs fine if you keep it below 2500 rpm and just apply light throttle. Heavier throttle application or higher rpms and it cuts out as if you turned off the key until you le...
September 19, 2011
1998 BMW 740iL 4.4L Misfire VIN: WBAGJ8329W
P0420: catalyst sys eff. below threshold. This car runs fine until you give it full throttle and the rpms get above about 4k rpm. It then starts to hesitate, doesnt feel exactly like a mifire more like it just starts to slow down. then the computer seems to turn off the cylinders that are misfiring. i...
September 28, 2011
2001 Nissan Sentra XE 1.8L Cuts out VIN: 3N1CB51D21
P0420: Catalyst Efficiency Below Normal. Car runs great when started cold until driven for about 5-15 miles. Then idles fine and runs fine if you keep it below 2500 rpm and just apply light throttle. Heavier throttle application or higher rpms and it cuts out as if you turned off the key until you le...
September 30, 2011
1999 Dodge Ram 1500 Truck 5.9L Poor Idle Quality, Misfire VIN: 3B7HF13Z0X
P0420: Catalyst Efficiency Below Normal (Bank 1). ... on and customer requested repairs be made in order to pass DEQ. Code came back as P0420: CAT Efficiency low. Read data stream while analysing emmisions; Both Pre CAT and Post CAT O2 sensors mimick each other. Readings are around 0.08 - 0.12V. Exhaust HC's ...
September 14, 2011
2001 Nissan Sentra XE 1.8L Cuts out VIN: 3N1CB51D21
P0420: Catalyst Efficiency Below Normal. Car runs great when started cold until driven for about 5-15 miles. Then idles fine and runs fine if you keep it below 2500 rpm and just apply light throttle. Heavier throttle application or higher rpms and it cuts out as if you turned off the key until you le...
September 19, 2011
1998 BMW 740iL 4.4L Misfire VIN: WBAGJ8329W
P0420: catalyst sys eff. below threshold. This car runs fine until you give it full throttle and the rpms get above about 4k rpm. It then starts to hesitate, doesnt feel exactly like a mifire more like it just starts to slow down. then the computer seems to turn off the cylinders that are misfiring. i...
September 28, 2011
2001 Nissan Sentra XE 1.8L Cuts out VIN: 3N1CB51D21
P0420: Catalyst Efficiency Below Normal. Car runs great when started cold until driven for about 5-15 miles. Then idles fine and runs fine if you keep it below 2500 rpm and just apply light throttle. Heavier throttle application or higher rpms and it cuts out as if you turned off the key until you le...
September 30, 2011