Lexus P0419 Secondary Air Injection System Relay B Circuit Malfunction

Description

OBD-II Trouble Code Description for P0420 Lexus

Catalyst System Efficiency Below Threshold

What does this mean?

OBD2 Code P0420 Lexus 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 Lexus 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 Lexus
You will likely not notice any drivability problems, although there may be symptoms.

Causes

Possible causes of OBD code P0420 Lexus
A code P0420 Lexus 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 Lexus 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 Lexus.com – P0420 Lexus Help

Related Codes

P0421 Lexus P0422 Lexus


The OBD2 Code Information Be Applicable For Lexus:

2013 Lexus RX 450h F Sport,2013 Lexus RX 450h,2013 Lexus RX 350 F Sport,2013 Lexus RX 350,2013 Lexus LX 570,2013 Lexus LS EU-Version,2013 Lexus LS 600h L,2013 Lexus LS 460 F Sport,2013 Lexus LS 460,2013 Lexus LF-NX Concept,2013 Lexus GS 450h F Sport,2013 Lexus GS 450h,2013 Lexus GS 350 F Sport,2013 Lexus GS 350,2013 Lexus GS 250,2013 Lexus ES 300h,2013 Lexus ES350,2012 Lexus LF-LC Concept,2012 Lexus LF-CC Concept,2011 Lexus LFA,2011 Lexus LF-Gh Concept,2011 Lexus IS 350 F Sport,2011 Lexus IS 350,2011 Lexus CT 200h,2010 Lexus SC 430,2010 Lexus RX 450h,2010 Lexus RX 350,2010 Lexus LS 600h,2010 Lexus LS 460 Sport,2010 Lexus LS 460 L,2010 Lexus IS250C,2010 Lexus HS 250h,2010 Lexus GX 460,2010 Lexus GS 460,2010 Lexus GS 450h,2010 Lexus GS 350,2010 Lexus ES 350,2009 Lexus SC430,2009 Lexus LS,2009 Lexus LS460,2009 Lexus LF-Ch,2009 Lexus IS 350,2009 Lexus GX 470,2009 Lexus GS 460,2009 Lexus GS 450h,2009 Lexus GS 350,2008 Lexus LX 570,2008 Lexus LS 600h L,2007 Lexus LS,2007 Lexus LF,2006 Lexus SC,2006 Lexus IS350,2006 Lexus GS,2005 Lexus RX400h,2005 Lexus LFA Concept,2005 Lexus ES330,2004 Lexus RX330,2004 Lexus LS430

 

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