Cadillac P0420 Catalyst System Efficiency Below Threshold Bank 1


OBD-II Trouble Code Description for P0421 Cadillac

Warm Up Catalyst Efficiency Below Threshold

What does this mean?

OBD2 Code P0421 Cadillac definition:
Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


Possible sumptoms of OBD code P0421 Cadillac
You will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days.


Possible causes of OBD code P0421 Cadillac
A code P0421 Cadillac may mean that one or more of the following has happened: The catalytic converter is no longer functioning properly An oxygen sensor is not reading (functioning) properly A sparkplug is fouled up

Possible Solutions

Measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). In fact, it would be a good idea to test each oxygen O2 sensor while you’re at it. One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it’s out of it’s bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It’s worth checking into.

Related Codes

P0420 Cadillac P0422 Cadillac P0423 Cadillac P0424 Cadillac P0425 Cadillac P0426 Cadillac P0427 Cadillac P0428 Cadillac P0429 Cadillac

The OBD2 Code Information Be Applicable For Cadillac

2013 Cadillac XTS,2013 Cadillac Elmiraj Concept,2013 Cadillac ATS,2012 Cadillac SRX,2011 Cadillac Ciel Concept,2011 Cadillac CTS Coupe,2011 Cadillac CTS-V Sport Wagon,2011 Cadillac CTS-V Coupe Race Car,2011 Cadillac CTS-V Coupe,2011 Cadillac CTS-V Black Diamond Edition,2010 Cadillac XTS Platinum Concept,2010 Cadillac Urban Luxury Concept,2010 Cadillac SRX,2010 Cadillac SLS,2010 Cadillac CTS Sport Wagon,2010 Cadillac Aera Concept,2009 Cadillac Presidential Limousine,2009 Cadillac Escalade Hybrid,2009 Cadillac Converj Concept,2009 Cadillac CTS-V,2008 Cadillac STS,2008 Cadillac Provoq Concept,2008 Cadillac Escalade Platinum,2008 Cadillac CTS Coupe Concept,2008 Cadillac CTS,2008 Cadillac BLS Wagon,2007 Cadillac SRX European Version,2007 Cadillac SLS,2007 Cadillac Escalade European Version,2007 Cadillac Escalade EXT,2007 Cadillac Escalade ESV,2007 Cadillac Escalade,2007 Cadillac BLS Sport,2006 Cadillac XLR Star Black Limited Edition,2006 Cadillac XLRV,2006 Cadillac STSV,2006 Cadillac SRX,2006 Cadillac Escalade ESVe Limousine,2006 Cadillac DTS Limousine,2006 Cadillac DTS,2006 Cadillac CTS,2006 Cadillac BLS,2005 Cadillac XLR Euro,2005 Cadillac STS SAE 100,2005 Cadillac STS Euro,2005 Cadillac STS,2005 Cadillac SRX Euro,2005 Cadillac SRX,2005 Cadillac CTS Euro,2005 Cadillac CTS-V Euro,2005 Cadillac BLS Show Car,2004 Cadillac XLR,2004 Cadillac Seville SLS,2004 Cadillac SRX,2004 Cadillac Escalade ESV Platinum,2004 Cadillac Escalade ESV Executive Edition,2004 Cadillac DeVille Armored,2004 Cadillac CTSV Race Car,2004 Cadillac CTSV,2004 Cadillac CTS,2003 Cadillac Sixteen Concept,2003 Cadillac Escalade EXT,2003 Cadillac Escalade ESV,2003 Cadillac CTSV with Accessories,2003 Cadillac CTS,2002 Cadillac Vizon Concept,2002 Cadillac Seville STS,2002 Cadillac Escalade EXT,2002 Cadillac Escalade,2002 Cadillac DeVille,2002 Cadillac Cien Concept,2001 Cadillac Seville,2001 Cadillac Eldorado,2001 Cadillac DeVille Presidential Limousine,2001 Cadillac DeVille DTS,2000 Cadillac Seville STS,2000 Cadillac Imaj Concept,2000 Cadillac Escalade,2000 Cadillac Eldorado ETC,2000 Cadillac DeVille



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