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Toyota Repair/Toyota Camry's check engine light


QUESTION: My toyota check engine light came on the next day after my battery replaced. I took it back to the dealer I was told my catalytic converter needs to be replaced. I took it to another mechanic and was told that the o2 sensors need to be replaced in addition to the converter. I drove it around for over a year with the check engine light on. It failed the emission test and they pulled 2 codes - 420 and 430. After the converter and sensors were replaced, the engine light came back on a few hours later. I took it back to the mechanic. They cleared it but hours later, it came back on again. Someone told me that the car's computer system needs to be re-booted by taking out the battery wires and let the car sit for a while and reconnect them. The mechanic doesn't seem to know what to do. How can I fix this problem?

ANSWER: Those codes are for the catalityc converter, so their diagnosis seems correct, it's possible they replaced the wrong converter, is this a 4 cylinder engine? What year is it and mileage?

---------- FOLLOW-UP ----------

QUESTION: It is a 2002 V6 Engine Toyota camry. How many converters does the 2002 Toyota Camry has? Does it mean that the they should not have replaced the o2 sensors and only the converter needed to be replaced?

Some repair shops recommend replacing the sensor when the converters go out usually as a preventive measure because they are a common failure part. There are actually three converters on this model, each cylinder bank has one just after the intake manifolds and there is another one downstream which is sort of a "clean up converter" but it seldom fails, can you find out exactly which converter was replaced? The diagnostic code should also indicate if it is bank 1 or bank 2, so I would need two things: which bank did the diagnostics say was the problem and which converter was replaced? The one for bank one(near the firewall) or bank two (near the radiator).  

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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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