A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.

When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed." property="og:description">

For Shop Owners

P0421 MITSUBISHI - Warm Up Catalyst Efficiency Below Threshold- Cylinders 1-4

Repair Importance Level: 2/3
Repair Difficulty Level: 2/3 What does this mean?

Possible causes

  • Warm Up Three Way Catalytic converter deterioration or malfunction
  • Exhaust system leaks
  • Loose front or rear HO2Ss
  • Faulty front heater O2 sensor
  • O2 sensors harness is open or shorted
  • O2 sensors poor electrical connection
What does this mean?

Tech notes

As the code description implies the P0421 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0421 code is combined with other codes, try fixing the other codes first.

There is a factory service recall for the following Mitsubishi Models:

2002 Mitsubishi Lancer
2003 Mitsubishi Lancer
2004 Mitsubishi Lancer
2005 Mitsubishi Lancer

What does this mean?

When is the code detected?

The P0421 code is set when PCM has determined that the warm up catalyst efficiency for bank 1 is below threshold for the current engine operating condition. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank)

Possible symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P0421 MITSUBISHI Description

The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).

A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.

When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.

OBDII Code P0421 Mitsubishi - Warm Up Catalyst Efficiency Below Threshold- Cylinders 1-4 - k1no-portal.ru

Need more help?

Do you need more help with the P0421 Mitsubishi code? Ask a question to our users or find an automotive repair shop near you to help fix the OBDII code

P0421 MITSUBISHI Comments

Help us improve k1no-portal.ru. Leave a comment below or tell us if the information above help you fix the code. What are the symptoms on your vehicle for the P0421 Mitsubishi code? Have you replaced any parts?
Any information is appreciated. Thanks
Repair Importance Level: 2
1=Low 2=Medium 3=High
Repair Difficulty Level: 2
1=Easy 2=Moderate 3=Hard

Browse All Codes For Specific Model YearBeta
Ford F150 1998 Ford F150
1999 Ford F150
2000 Ford F150
2001 Ford F150
2002 Ford F150
2003 Ford F150
Ford Fusion 2006 Ford Fusion
2007 Ford Fusion
2008 Ford Fusion
2009 Ford Fusion
2010 Ford Fusion
2011 Ford Fusion
2012 Ford Fusion
Honda Accord 2008 Honda Accord
2009 Honda Accord
2010 Honda Accord
Honda Civic 1996 Honda Civic
1997 Honda Civic
1998 Honda Civic
1999 Honda Civic
2000 Honda Civic
Infiniti G35 2003 Infiniti G35
2004 Infiniti G35
2005 Infiniti G35
2006 Infiniti G35
Nissan Altima 2002 Nissan Altima
2003 Nissan Altima
2004 Nissan Altima
2005 Nissan Altima
2006 Nissan Altima
2008 Nissan Altima
2009 Nissan Altima
2010 Nissan Altima
2011 Nissan Altima
2012 Nissan Altima
Nissan Maxima 2005 Nissan Maxima
2006 Nissan Maxima
2007 Nissan Maxima
2008 Nissan Maxima
Nissan Pathfinder 2005 Nissan Pathfinder
2006 Nissan Pathfinder
2007 Nissan Pathfinder
2008 Nissan Pathfinder
2009 Nissan Pathfinder
2010 Nissan Pathfinder
2011 Nissan Pathfinder
2012 Nissan Pathfinder
Nissan Rogue 2008 Nissan Rogue
2009 Nissan Rogue
2010 Nissan Rogue
2011 Nissan Rogue
2012 Nissan Rogue
2013 Nissan Rogue
Nissan Sentra 2002 Nissan Sentra
2003 Nissan Sentra
2004 Nissan Sentra
2005 Nissan Sentra
2006 Nissan Sentra
2007 Nissan Sentra
2008 Nissan Sentra
2009 Nissan Sentra
2010 Nissan Sentra
2011 Nissan Sentra
2012 Nissan Sentra
Toyota Camry 1997 Toyota Camry
1998 Toyota Camry
1999 Toyota Camry
2000 Toyota Camry
2001 Toyota Camry
2006 Toyota Camry
2007 Toyota Camry
2008 Toyota Camry
2009 Toyota Camry
2010 Toyota Camry
2011 Toyota Camry
Toyota Corolla 2005 Toyota Corolla
Toyota Echo 2000 Toyota Echo
2001 Toyota Echo
2002 Toyota Echo
Toyota Highlander 2001 Toyota Highlander
2002 Toyota Highlander
2003 Toyota Highlander
2004 Toyota Highlander
2005 Toyota Highlander
2006 Toyota Highlander
2007 Toyota Highlander
Toyota Prius 2004 Toyota Prius
2005 Toyota Prius
2006 Toyota Prius
2007 Toyota Prius
2008 Toyota Prius
2009 Toyota Prius
Scion xB 2005 Scion xB
2006 Scion xB
2007 Scion xB
Advertisement
Home - For Shop Owners - About k1no-portal.ru - Privacy Policy - Terms and Conditions - - Copyright 2010-2018 k1no-portal.ru
k1no-portal.ru - - - -
Posted and Edit by 06-14-2015

Related pages


what is code p07002007 hyundai elantra transmission fluid2001 ford windstar egr valvetoyota highlander heater control problemsnissan sentra 2002 enginevw golf crankshaft sensor2007 ford expedition spark plugsevap large leakp0132 codecatalytic converter acura rsxbattery for 2006 toyota corollajeep liberty codes2007 nissan altima cvt transmission problemserror code 1309p0442 oldsmobile alerosupercharged 6.5 dieselturbo boost pressure sensorobd code p0456hydraulic converterp0420 code nissan altima 2005what does the electronic throttle control light mean2010 jeep compass transmission problems1998 honda accord alternator09 acura tl type s2007 uplander transmission problemsacura tsx automatic transmission problemscar code p0340acura mdx maintenance codesp0174 ford mustanghonda code b12003 mitsubishi eclipse intake manifoldhonda accord mass air flow sensorvios timing beltcode p1456po351 code2006 nissan murano oil type2006 saturn ion check engine lightwhat is the obd system checkobd2 codes honda2005 ford 5.4 engine problems2004 kia spectra enginewhat is a manifold absolute pressure sensor1998 infiniti i30t2006 kia optima parts2006 cts 3.62001 jeep wrangler clutch replacementchrysler 300m engine problems2002 toyota prius problems98 honda odysseyvw beetle secondary air pump2004 chevy aveo transmission2003 infiniti qx4 problemspo420 code toyotadecode toyota vin numberp2714isuzu trooper transmission fluidnissan quest ecmhonda cel codescatalytic converter chrysler pacifica98 honda civic oilwhat is a p0420 check engine codeinfiniti m36xford fiesta tsbcode p0325p0340 trouble code2003 chevy silverado v62005 nissan altima fusesshift solenoid symptomshonda civic hybrid problems1997 infiniti q45tp0133 toyotacrankshaft sensor nissan altima 2006po715 codehonda transmission codes2002 nissan sentra head gasket