Air/fuel sensor failure

[fathom]

I've posted this on a usenet forum several days ago, but got no answers, so now you folks are court of last resort.

'03 Five-speed manual, 4-cyl. Camry, made in Japan. Seven months after purchase, "check engine light" pops on.

Dealer says Air-Fuel sensor (in manifold behind radiator) went bad. Ordered in new sensor, but it was the wrong part. There was some days of back-forth between the dealer and "toyota techs" until they finally determined that no matter what the book said, the replacement sensor was not the right part, so they finally ordered in the correct part -- which they called a "national part."

Fine. All fixed. Well, not so fast, seven months later same sensor goes out. I make noise about there being some other problem causing the sensor failure, but finally agree to shut-up and go away. After all, this is all being done under warranty.

Well, eight months later, guess what? Same sensor goes out. This is strike three at 33K miles.

I'm taking it in to the dealer in a couple of days, but I really am concerned that something "upstream" is causing this problem. I change oil and filter every 3k, use Chevron gasoline 99 percent of the time, and swapout the air filter every 10K

Any thoughts?

[chronoti]

do you normaly get that gas form the same gas station?

[fathom]

I split between about three Chevron stations in the area. All would be supplied by the same oil jobber though.

[rat42]

I have seen intermittent CEL's on my 92 ES ( camry in drag ) from high etoh in the gas i think. I was in the middle of checking it out when it got totalled.

[chronoti]

i would almost hate to say maybe there might be a problem in the gas that might be causeing that (small leak in there tank or salt from the winter months). maybe try some diffrent gas after this change and see if it does it again

[fathom]

Originally Posted by chronoti

i would almost hate to say maybe there might be a problem in the gas that might be causeing that (small leak in there tank or salt from the winter months). maybe try some diffrent gas after this change and see if it does it again

I suppose anything is possible, but the stations I've been going to are probably the most popular in the area (not that there is that MUCH available in my area) and we don't have snow, so no salt problems.

Just wondering whether there is any sort of diagnostic they should run before they just slap another sensor in....and eventually, I'll be out of warranty here fairly quick.

[500KCamry]

Originally Posted by fathom

Dealer says Air-Fuel sensor (in manifold behind radiator) went bad. Ordered in new sensor, but it was the wrong part. There was some days of back-forth between the dealer and "toyota techs" until they finally determined that no matter what the book said, the replacement sensor was not the right part, so they finally ordered in the correct part -- which they called a "national part."

???? Sounds weird to me.

[chronoti]

well shell gas has had a problem with sulfur amounts in it's gas that caused a whole set of problems like that (well around here at least) it might be a thing it might be something else but chances are it's going to be something like that, also before you take it this time mark the old sensor and check it back when you get it back, they my just be cleaning the old one up a little and not giving you a new part.

[fathom]

Well, OP again.

I nicely made the comment when I took the car in today, that it would be nice if they checked to see if something else was the problem rather than just replace the sensor once again.

They apparently worked with the mystical Toyota Tech desk in some far-off land and decided to replace the ECM. Since my indy mechanic had told me that he suspected that might be the cause, I am feeling a little better.

Of course, it must be ordered....but better Toyota rather than I eat that $1200 parts bill.