Questions and Answers

Toyota O2 Sensors Q. Vincent, I love your web site. I have a question: My Toyota Sienna 1998 has a Check Engine Light and I took it to the dealership today and after they checked it they said it was due to bad O2 sensors and catalytic converter. The catalytic converter is covered under warranty but the sensors are not.

They want over $600.00 to change the sensors. The milage in the vehicle is 56,000 and I was wondering if it is normal for them to go this early. I read somebody saying in your web site that usually they go bad because of a rich mix. My question is: how difficult would it be for me to change the O2 sensors? I have changed a timing belt an other elaborate maintenance tasks on a Toyota Camry and a Celica. The cost of the sensors at the dealership is $280 for both. Would it be worth it to do it myself?

Thanks

A. Those O2 sensors are not difficult to change at all. They just unscrew from the exhaust pipe and you screw the new ones in. There is a special O2 sensor socket you can get to take them out, but if you have a good box wrench of the proper size (I think it's 22 mm) that will work as well.

It's not usual for them to go bad at this milage, but neither is it unheard of. I would want to be sure that they are bad before I replace them. Sometimes a bad O2 sensor code is indicative of another problem.

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