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Toyota Repair/VSC and Check engine lights


My 2002 Highlander V6 4WD is giving a "P0420" code for catalytic converter not meeting performance standards according to the output from my converter output oxygen sensor.  Is it possible that anything other than a poor performing converter to cause this code ?  Also another post I saw mentioned vacuum hoses off would be a good thing to check. I checked and found 3 hoses near air filter, 2 connected and one stub with a plug in it ? ? ?  Is that by design ?

Look forward to hearing your professional opinion,
And definitely don't look forward to a $1200 converter job.

Thanks Ted.       Pete

The P0420 code is pretty much specific to a cat converter problem,i can also be caused by other engine problems like a lean run condition but you are not getting any other codes. Have you looked around the air filter area for any hoses that may be off that should be on that connector you mentioned, did you recently buy it or have you owned it longer?

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Ted Ritter


I have more than 28 years experience as toyota technician, I will be able to answer most questions related to the Toyota product line up to the present year models,I am located in the US but welcome questions from other regions of the world. When asking a question please provide specific information: year,model, engine,transmission information. Provide as much information as possible including a brief repair history if possible. I have been a volunteer here for more ten years an have answered over 16,000 questions helping Toyota owners with their problems and save thousands of dollars without any compensation, some of my answers are published on many other websites including google and various automotive forums. DONATIONS ARE VERY MUCH APPRECIATED, IF YOU HAVE RECIEVED HELPFUL INFORMATION PLEASE MAKE A DONATION. AS OF TODAY (JULY 22, 2014) ALL REQUESTED GRAPHICS, ILLUSTRATIONS, DIAGRAMS, PHOTOS, WILL REQUIRE THE MINUMUM DONATION UP FRONT.


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