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P0420 Diagnostic Trouble Code Discussion for December 2007

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1998 Toyota Sienna LE 3.0L Poor Fuel Economy, MIL Lamp on VIN: 4T3EZF13C9
P0420: Catalyst Efficiency Below Normal (Bank 1). ... has me lost. Code p0420 low cat efficiency bank 1. Bank 1 sensor switching but slow. Replaced o2 sensor with aftermarket NGK sensor. Sensor readings better. Retuned to customer. One month later code is back. Graph O2 sensor, switching slow again like a slu...
December 13, 2007
2002 Volkswagen Jetta GLS 1.8L MIL Lamp on VIN: 3VWSE69M72
P0420: . ... appearing of p0420.
December 14, 2007
2005 Honda Pilot EX 3.5L Misfire, MIL Lamp on VIN: 5FNYF18485
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... codes for #3 and #6 cyls. During our road tests,p0420 Cat efficiency below threshold-bank one, set also. We performed tune-up with dealer oem plugs. Car still has a ramdom intermittent misfire on any cyl it want to. Not just ...
December 31, 2007