QuestionQUESTION: Hello, I bought a used 01 limited 4runner recently. The engine light came on yesterday out of the blue. A code reader revealed the following:
code P0420
"catalyst system efficiency below threshold - bank 1"
"probable cause
aa1 - air leak in exhaust before rear H02S bank 1
aa2 - AF sensor error
aa3 - fuel system fault
aa3 - faulty catalytic converter"
I looked under the car and found 2 catalytic converters so I guess I have a Cali version, which is weird because the carfax says it was bought new in MA.....anyway, any ideas on my problem? Thank you
ANSWER: Is it a V-6 or 4 cylinder? How many miles on the odometer? :ook under the hood label and see if it's california certified or does it say USA/Canada?
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QUESTION: Ted, It is a 3.4 V6 and it says "certified OBD II USA/Canada" (sorry, I mistook a device up near the manifold for another cat)... I'm glad to hear it's not a Cali though.
It has 171,000 miles.
Thanks
ANSWER: It has actually two converters, the main and a sub cat, the one that usually causes the problem is the main cat attached to the exhaust manifold on the right side, at this mileage I would recommend replacing the cat as well as both the o2 sensors.
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QUESTION: Thanks for your help Ted..... just to clarify, is my model a California model or not? What part of the label told you what it was?
thanks
AnswerIt's what is referred to as a Federal vehicle, to be sold outside california but that doesn't mean it can't be registered in california, reading all of the print on the label will show that it's also certified to california emission standards, when buying emission control parts there is usually a small difference in the parts so the part numbers will be different and usually the toyota parts department will ask if it's a "federal or california veh". If it was sold exclusively in california the large print on the label will say "Certified OBD II California".
