2000 Toyota 4Runner Check Engine Light
Sounds to me the dealer is attempting to fix the problem by changing things that
COULD be the problem. You say the car runs fine and there are no other symptoms. If the cats were bad you should (not Always) have some type of sign. Do they get hotter than normal. The way you would know is you would probably feel the heat generated by them through the floor board. Also check them in the dark after the car is warmed up and see if they glow (cherry red). These are both signs of the cats being clogged but you should also have poor engine performance. If you don't have these signs theycould still be badThe o2 senors could be tested with a tester if you have one. If I had to change one or the other I would change the o2 senors first because they are cheaper to replace and more likely to go bad than the cats.
Hope this helps :) Backyardmechanic[/b]
I plan to take the car to a different Toyota dealer and see what they say. It certainly seems like I have nothing to lose by changing the O2 sensors first and then see what happens. Sounds logical--and like you said, a lot cheaper!
I appreciate the help.
Suggested Repair
Do not replace both catalytic converters and oxygen sensors based only on the dealer quote. Check for signs of clogged converters, such as excessive underfloor heat, a cherry-red glow, or poor performance. Test the oxygen sensors and replace faulty sensors first, then recheck the light and get a second opinion.
Conversation Summary
The owner of a 2000 Toyota 4Runner with 103,000 miles reported a check engine light but no drivability problems. A dealer recommended two catalytic converters and both oxygen sensors for about $2,500. The expert said this may be replacing unconfirmed parts, noted that bad converters often produce heat, glowing, or poor performance, and advised testing and replacing the cheaper oxygen sensors first. The owner planned to seek a second opinion and try the sensors first.
