Buick P0419 Secondary Air Injection System Relay B Circuit Malfunction

Description

OBD-II Trouble Code Description for P0420 Buick

Catalyst System Efficiency Below Threshold

What does this mean?

OBD2 Code P0420 Buick definition:
The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 Buick code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that 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 P0420 Buick
You will likely not notice any drivability problems, although there may be symptoms.

Causes

Possible causes of OBD code P0420 Buick
A code P0420 Buick may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for An oxygen sensor is not reading (functioning) properly The engine coolant temperature sensor is not working properly Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe Retarded spark timing The oxygen sensors in front and behind the converter are reporting too similar of readings

Possible Solutions

Some suggested steps for troubleshooting a P0420 Buick error code include: Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required. Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady). Inspect the downstream heated oxygen sensor (HO2), replace if necessary Replace the catalytic converter 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. See also: P0420 Buick.com – P0420 Buick Help

Related Codes

P0421 Buick P0422 Buick


The OBD2 Code Information Be Applicable For Buick

2013 Buick Verano Turbo,2013 Buick Riviera Concept,2013 Buick Encore,2013 Buick Enclave,2012 Buick Verano,2012 Buick Regal GS,2011 Buick Regal,2011 Buick LaCrosse GL Concept,2011 Buick GL8,2011 Buick Envision Concept,2010 Buick Regal GS Concept,2010 Buick LaCrosse,2009 Buick Business Concept,2008 Buick Lucerne Super,2008 Buick LaCrosse Super,2008 Buick LaCrosse CXS,2008 Buick Invicta Concept,2008 Buick Enclave,2007 Buick Riviera Concept Coupe,2006 Buick Terraza,2006 Buick Rendezvous CXL,2006 Buick Rainier CXL,2006 Buick Lucerne CXS,2006 Buick Enclave Concept,2005 Buick Terraza CXL,2005 Buick Royaum,2005 Buick Rendezvous CX,2005 Buick Park Avenue,2005 Buick LeSabre Celebration Edition,2005 Buick LaCrosse CXS,2005 Buick LaCrosse CSX,2005 Buick Century,2004 Buick Velite Concept,2004 Buick Rendezvous Ultra,2004 Buick Regal Abboud GS,2004 Buick Rainier,2004 Buick Park Avenue Ultra,2003 Buick Rendezvous,2003 Buick Park Avenue Ultra,2002 Buick Rendezvous,2002 Buick Regal,2002 Buick LeSabre Custom,2001 Buick Regal,2001 Buick Park Avenue Ultra,2001 Buick Park Avenue,2001 Buick LeSabre,2001 Buick Blackhawk Concept,2001 Buick 2-2 Bengal Roadster Concept,2000 Buick Regal GNX Show Car,2000 Buick Regal Cielo Concept,2000 Buick Regal,2000 Buick Park Avenue,2000 Buick LeSabre Limited,2000 Buick Century

 

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