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P0420 Diagnostic Trouble Code Discussion for November 2013

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2010 Kia Soul Sport 2.0L MIL Lamp on VIN: KNDJT2A26A
P0420: Catalyst System Efficiency below Threshold Bank 1. [...] 1 replaced. Checked for exhaust and intake leaks...none found. Checked wiring with ohm meter..all good. checked fuel pressure...within spec. Was told by customer they hit a pot hole and 2 hours after the light came on. They had it at the dealer who repla...
November 04, 2013
2003 Pontiac Vibe GT 1.8L MIL Lamp on VIN: 5Y2SN64L53
P0420: Catalyst System Low Efficiency. this vibe sets these 3 codes after 2 drive cycles and approx. 8 miles. watching scan data I can see bnk 1 o2 sensor cycling between .085-.795 volts but the cycles are very slow taking approx 4-5 seconds at idle and about 3 seconds at cruise. stft cycles from -...
November 05, 2013
2010 Kia Soul Sport 2.0L MIL Lamp on VIN: KNDJT2A26A
P0420: Catalyst System Efficiency below Threshold Bank 1. [...] 1 replaced. Checked for exhaust and intake leaks...none found. Checked wiring with ohm meter..all good. checked fuel pressure...within spec. Was told by customer they hit a pot hole and 2 hours after the light came on. They had it at the dealer who repla...
November 06, 2013
2005 Mercury Sable GS 3.0L Poor Idle Quality, Hesitation, Surge, MIL Lamp on VIN: 1MEFM50U95
P0420: catalyst efficiency. Vehicle originally came in for a misfire. Typical dead miss felt with code po301 cylinder 1 misfire. Plug was wet. Misfire and code went away with replacement of coil wires and plug. Catalytic converter efficiency codes remains. Removed converters to check fo...
November 10, 2013
1999 Lexus ES300 3.0L MIL Lamp on VIN: JT8BF28G5X
P0420: Catalyst Efficiency Below Normal (Bank 1). Car came in with p0420 code . Replaced rear bank ( y-pipe type ) converter (by way of advice from Toyota tech). Car came back with P0420 code. Car has 3 converters and only one downstream o2 sensor. will this car ever set a p0430 bank 2 converter code. I am gu...
November 14, 2013
2010 Kia Soul Sport 2.0L MIL Lamp on VIN: KNDJT2A26A
P0420: Catalyst System Efficiency below Threshold Bank 1. [...] 1 replaced. Checked for exhaust and intake leaks...none found. Checked wiring with ohm meter..all good. checked fuel pressure...within spec. Was told by customer they hit a pot hole and 2 hours after the light came on. They had it at the dealer who repla...
November 04, 2013
2003 Pontiac Vibe GT 1.8L MIL Lamp on VIN: 5Y2SN64L53
P0420: Catalyst System Low Efficiency. this vibe sets these 3 codes after 2 drive cycles and approx. 8 miles. watching scan data I can see bnk 1 o2 sensor cycling between .085-.795 volts but the cycles are very slow taking approx 4-5 seconds at idle and about 3 seconds at cruise. stft cycles from -...
November 05, 2013
2010 Kia Soul Sport 2.0L MIL Lamp on VIN: KNDJT2A26A
P0420: Catalyst System Efficiency below Threshold Bank 1. [...] 1 replaced. Checked for exhaust and intake leaks...none found. Checked wiring with ohm meter..all good. checked fuel pressure...within spec. Was told by customer they hit a pot hole and 2 hours after the light came on. They had it at the dealer who repla...
November 06, 2013
2005 Mercury Sable GS 3.0L Poor Idle Quality, Hesitation, Surge, MIL Lamp on VIN: 1MEFM50U95
P0420: catalyst efficiency. Vehicle originally came in for a misfire. Typical dead miss felt with code po301 cylinder 1 misfire. Plug was wet. Misfire and code went away with replacement of coil wires and plug. Catalytic converter efficiency codes remains. Removed converters to check fo...
November 10, 2013
1999 Lexus ES300 3.0L MIL Lamp on VIN: JT8BF28G5X
P0420: Catalyst Efficiency Below Normal (Bank 1). Car came in with p0420 code . Replaced rear bank ( y-pipe type ) converter (by way of advice from Toyota tech). Car came back with P0420 code. Car has 3 converters and only one downstream o2 sensor. will this car ever set a p0430 bank 2 converter code. I am gu...
November 14, 2013