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P0420 Diagnostic Trouble Code Discussion for September 2006

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2001 Subaru Outback 2.5L MIL Lamp on VIN: 4S3BH67571
P0420: Catalyst Efficiency Below Normal (Bank 1). this is the 3rd time this car has set this code it ussually happens about every 3 months, one time it had a dead front o2 sensor so we replaced it. when we get our hands on it every thing tests good, All tests lead to replacing converters but that is a lot of ...
September 11, 2006
2000 Infiniti I30 3.0L Excessive Emissions, Poor Fuel Economy, MIL Lamp on VIN: JNKCA31A8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). hello laddys and genttle man: we are not sure what to do to this car. code indicated cat problem and the cat is not working most of the time, because the engine is running too rich. the mass air flow is prime suspect, but don't know what it should look like. t...
September 14, 2006
2000 Volkswagen Passat GLS 2.8L MIL Lamp on VIN: WVWTTH23B5
P0420: Cat Efficency. ... code. Sorry but I really don't VW's much. This is the history of this car since 9-1-06. Car comes in for inspection with check engine light on, P0139 O2 heater, replace O2. Dealer sends O2 for AHA engine and we have ATQ, so we get new code O2 heater short ...
September 20, 2006
2000 Volkswagen Passat GLS 2.8L MIL Lamp on VIN: WVWTTH23B5
P0420: Cat Efficency. ... code. Sorry but I really don't VW's much. This is the history of this car since 9-1-06. Car comes in for inspection with check engine light on, P0139 O2 heater, replace O2. Dealer sends O2 for AHA engine and we have ATQ, so we get new code O2 heater short ...
September 21, 2006
1996 Chevrolet K1500 Cheyenne 5.7L Excessive Emissions VIN: 1GCEK19M3T
P0420: Catalyst System Low Efficiency (Bank 1). ... problem was P0300 random misfire only on load. After trying everything I finally replaced all injectors with the GM conversion kit from CSFI to MFI injectors. This fixed the misfire problem. It runs perfect. But... imedeatly after injector replacement SES ...
September 26, 2006
1997 Toyota Camry CE 3.0L MIL Lamp on VIN: 4T1BF22K7V
P0420: Catalyst Efficiency Below Normal (Bank 1). ... 40,000 miles ago with a code P0420. We had a after market converter put on it and the code came back so we put a OE converter and it was good for 40,000 miles. Now its back and we put another OE converter on it and it passes the monitor. The question I hav...
September 26, 2006
1996 Pontiac Grand Am SE 2.4L catalyst monitor VIN: 1G2NE12T3T
P0420: Catalyst System Low Efficiency. hello everyone , hope you can direct us to a repair or info on how to determine a solution to a catalyst monitor that wont run . vehicle came in with 4 codes , rear o2 slow, cat low efficiency, knock sensor activity , rich bank 1, weve got it all repaired and ...
September 27, 2006
1996 Pontiac Grand Am SE 2.4L catalyst monitor VIN: 1G2NE12T3T
P0420: Catalyst System Low Efficiency. hello everyone , hope you can direct us to a repair or info on how to determine a solution to a catalyst monitor that wont run . vehicle came in with 4 codes , rear o2 slow, cat low efficiency, knock sensor activity , rich bank 1, weve got it all repaired and ...
September 29, 2006
2002 Subaru Legacy GT 2.5L Poor Fuel Economy, MIL Lamp on VIN: 4S3BH64592
P0420: Catalyst Efficiency Below Normal (Bank 1). ... want to stay gone. originally came in with a P0172 fuel trim too rich and the dealer said it needed a air fuel ratio sensor. we installed a factory sensor as per dealer info and the light came on with the same code a week later.cleared the code and the lig...
September 29, 2006
2001 Subaru Outback 2.5L MIL Lamp on VIN: 4S3BH67571
P0420: Catalyst Efficiency Below Normal (Bank 1). this is the 3rd time this car has set this code it ussually happens about every 3 months, one time it had a dead front o2 sensor so we replaced it. when we get our hands on it every thing tests good, All tests lead to replacing converters but that is a lot of ...
September 11, 2006
2000 Infiniti I30 3.0L Excessive Emissions, Poor Fuel Economy, MIL Lamp on VIN: JNKCA31A8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). hello laddys and genttle man: we are not sure what to do to this car. code indicated cat problem and the cat is not working most of the time, because the engine is running too rich. the mass air flow is prime suspect, but don't know what it should look like. t...
September 14, 2006
2000 Volkswagen Passat GLS 2.8L MIL Lamp on VIN: WVWTTH23B5
P0420: Cat Efficency. ... code. Sorry but I really don't VW's much. This is the history of this car since 9-1-06. Car comes in for inspection with check engine light on, P0139 O2 heater, replace O2. Dealer sends O2 for AHA engine and we have ATQ, so we get new code O2 heater short ...
September 20, 2006
2000 Volkswagen Passat GLS 2.8L MIL Lamp on VIN: WVWTTH23B5
P0420: Cat Efficency. ... code. Sorry but I really don't VW's much. This is the history of this car since 9-1-06. Car comes in for inspection with check engine light on, P0139 O2 heater, replace O2. Dealer sends O2 for AHA engine and we have ATQ, so we get new code O2 heater short ...
September 21, 2006
1996 Chevrolet K1500 Cheyenne 5.7L Excessive Emissions VIN: 1GCEK19M3T
P0420: Catalyst System Low Efficiency (Bank 1). ... problem was P0300 random misfire only on load. After trying everything I finally replaced all injectors with the GM conversion kit from CSFI to MFI injectors. This fixed the misfire problem. It runs perfect. But... imedeatly after injector replacement SES ...
September 26, 2006
1997 Toyota Camry CE 3.0L MIL Lamp on VIN: 4T1BF22K7V
P0420: Catalyst Efficiency Below Normal (Bank 1). ... 40,000 miles ago with a code P0420. We had a after market converter put on it and the code came back so we put a OE converter and it was good for 40,000 miles. Now its back and we put another OE converter on it and it passes the monitor. The question I hav...
September 26, 2006
1996 Pontiac Grand Am SE 2.4L catalyst monitor VIN: 1G2NE12T3T
P0420: Catalyst System Low Efficiency. hello everyone , hope you can direct us to a repair or info on how to determine a solution to a catalyst monitor that wont run . vehicle came in with 4 codes , rear o2 slow, cat low efficiency, knock sensor activity , rich bank 1, weve got it all repaired and ...
September 27, 2006
1996 Pontiac Grand Am SE 2.4L catalyst monitor VIN: 1G2NE12T3T
P0420: Catalyst System Low Efficiency. hello everyone , hope you can direct us to a repair or info on how to determine a solution to a catalyst monitor that wont run . vehicle came in with 4 codes , rear o2 slow, cat low efficiency, knock sensor activity , rich bank 1, weve got it all repaired and ...
September 29, 2006
2002 Subaru Legacy GT 2.5L Poor Fuel Economy, MIL Lamp on VIN: 4S3BH64592
P0420: Catalyst Efficiency Below Normal (Bank 1). ... want to stay gone. originally came in with a P0172 fuel trim too rich and the dealer said it needed a air fuel ratio sensor. we installed a factory sensor as per dealer info and the light came on with the same code a week later.cleared the code and the lig...
September 29, 2006