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P0420 Diagnostic Trouble Code Discussion for March 2006

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2000 Toyota Celica GT 1.8L Excessive Emissions, Surge, Cuts out, Stall, Misfire, MIL Lamp on, pig rich exhaust VIN: JTDDR32T3Y
P0420: Catalyst Efficiency Below Normal (Bank 1). blocked off purge when problem occurred- nochange- motorvac 4k ago, pulled coils and switched- misfire remained at #2, pulled injectors and moved to diff. cylinders. fuel rail full of brown "coffee grounds"-since then rich condition has occured only on...
March 03, 2006
1998 Lexus LS400 4.0L MIL Lamp on VIN: JT8BH28F5W
P0420: Catalyst Efficiency Below Normal (Bank 1). With these codes I'm wondering if cat's are bad with this high miles.Or I'm looking at the wrong thing.MAF or something else.My scanner is down, and will not have back for another two or three weeks.I got codes from a read only unit.Should I run this car on th...
March 06, 2006
2001 Infiniti I30 3.0L MIL Lamp on VIN: JNKCA31A91
P0420: Catalyst Efficiency Below Normal (Bank 1). ... This Infiniti has been back to our shop three times and is coming back right now for good ol #4. First visit mil on, code P0420 present, at that time we found TSB for Bank 1 sensor 1 and front cat replacement along with ECM ...
March 09, 2006
1999 Chevrolet Tahoe LS 5.7L lack of acceleration VIN: 1GNEC13R9X
P0420: Catalyst System Low Efficiency (Bank 1). hi guys and gals, boy it seems i get the odd ones...heres my story...vehicle came in with lack of power complaint.. customer says it wont accelerate...first test was the fuel pressure...68 psi koeo and holding.running @58 psi checked timing it is ok...checked ...
March 13, 2006
1997 Ford F-150 Lariat 4.6L MIL Lamp on VIN: 1FTDX18W3V
P0420: catalyst effic below threshold b1. came in with codes p0420 & p0430 no action on scan tool for either rear sensor (flat line) both have 12 volts coming to them. so i replaced both sensors and still no response. what am i overlooking here? i'm covered up with work so probably something stari...
March 13, 2006
1997 Ford Crown Victoria 4.6L MIL Lamp on VIN: 2FALP71W5V
P0420: Cat System Efficiency Below Threshold Bank 1. I have a question for the Ford techs. We have had many problems with these 97 Crown Vics setting codes for the cat efficiency. We have made a real effort to fix these problems or find out what is causing the problem but we have never come up with a solution an...
March 15, 2006