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P0420 Diagnostic Trouble Code Discussion for May 2007

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1996 Toyota Camry LE 3.0L MIL Lamp on VIN: 4T1BF12K8T
P0420: Catalyst Efficiency Below Normal (Bank 1). ... cracked flex which is part of the converter. We replaced the cat (10/05 from DEC in CA) and it came back with a P0420. We replaced the cat again (another DEC) ... P0420. And again (4/07 this time a Bosal unit)... P0420 again 1 month later. So we tried ev...
May 08, 2007
1996 Toyota Camry DX 2.2L ODBII drive cycle VIN: 4T1BG12K2T
P0420: Catalyst Efficiency Below Normal (Bank 1). ... Emissions testing. Customer came in with P420 - Cat Eff low. We reset codes and sent him home with instructions to return is MIL reset. He was back in three days... same P0420. We changed out both O2 Sensors, cleared codes and sent him home with instructi...
May 15, 2007
2002 Volkswagen Cabrio GLS 2.0L Poor Idle Quality, Cuts out, Misfire, Poor Fuel Economy, MIL Lamp on VIN: 3VWCC21V12
P0420: catalist system cylinder 1. Vehicle came in with cel on and running so badly vehicle would hardly move. Cleared all codes, and vehicle ran better but seems to have a lack of power. When service manager tried to drive overnight, it only went about 4 miles when a cel came on and started fl...
May 22, 2007
1995 Jaguar XJS 4.0L Hesitation VIN: SAJNX2744S
P0420: catalyst below threshold bank1. with modis on generic obd2 lt fueltrim is at -89% on both banks and when code is cleared or battery is disconected to clear adaption fuel trim stays at -89% will not go back to 0%.which means the ecu is taking away fuel. also the maf is .03 grams per sec. at i...
May 25, 2007
2001 Acura MDX 3.5L MIL Lamp on VIN: 2HNYD18291
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... I've seen with a P0420 code after replacing stock converter with a remanufactured converter. All converters replaced have had good emissions numbers as in this one which happens to be a ULEV. Prior solutions to the low efficiency code have included a PCM r...
May 31, 2007