Description
OBD-II Trouble Code Description for P0421 Subaru
Warm Up Catalyst Efficiency Below Threshold
What does this mean?
OBD2 Code P0421 Subaru 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.
Symptoms
Possible sumptoms of OBD code P0421 Subaru
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.
Causes
Possible causes of OBD code P0421 Subaru
A code P0421 Subaru 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.
The OBD2 Code Information Be Applicable For Subaru:
2013 Subaru WRX Concept,2013 Subaru Viziv Concept,2013 Subaru Outback,2013 Subaru Legacy,2013 Subaru Impreza,2013 Subaru BRZ,2012 Subaru XV,2012 Subaru Impreza,2011 Subaru XV Concept,2011 Subaru Outback,2011 Subaru Impreza,2011 Subaru Forester,2010 Subaru Legacy,2010 Subaru Impreza,2009 Subaru Impreza,2008 Subaru Impreza,2008 Subaru Forester,2006 Subaru Impreza,2005 Subaru R1,2005 Subaru Pleo,2004 Subaru Impreza,2004 Subaru Forester,2003 Subaru Traviq
Note:
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