oxygen sensor on tow vehicles

[BK]

Since we all tow, I thought I would pass on some info on the oxygen sensor. My engine light came on in the dash and the car manual only said to take it to the dealer for repair. They charged me $82 to tell me that this engine light in the dash means you need to replace the Toyota oxygen sensor for $480. I talked with a mechanic and found out this sensor is located either on the exhaust manifold or before or after the catalic converter. Mine is after the converter. It looks like a spark plug and either unscrews or as mine has 2 screws that hold it in place. I just cleaned out the holes in the sensor and put it back in and it runs fine. I saved $400.

[Don T]

Hello:
Just to add some info here so folks are not misled. The O2 sensor uses a rare earth to sense oxygen level. It samples both outside and exhaust flow. Your low cost fix makes sense in this regard. The element in the sensor has to be hot enough to melt and will produce .45 volts at a very low current when fuel air mixture (without misfire) are at 14.7/1. The element is used up over time and at some point the sensor will begin to report lean mixture to the ECM (volts go low). The sensor can be ruined by antifreeze or curing RTV silicone that isn't "O2 sensor safe." Sensors not in the exhaust manifold will generally have more than two wires and have a heater installed to speed warmup. As the sensor ages periods of lean engine operation (momentary de-accelleration after hard pull) may make the sensor output negative voltage. Ecm will flash "Check Engine" light (with or without code being set) and engine may stumble. Normal operation will resume or you may have to shut down the engine and restart.
As for the $400.00, welcome to the "cheap to buy and then commited to replacement part necessities" marketing strategy. A GM sensor costs around $50.00. Got to love it.

[Frank C]

Bob,
Just curious to know how many miles on your toyota?

Don,
what might be the average miles on a GM needing this replacement?

[Joe 26M Time Warp]

SPeaking of 02 sensors, I changed out the entire exhaust system with the motor & trans. The sensor was located just forward of the catalytic converter and the threads held while the welded fitting broke off the pipe. A little hacksaw work recovered it.
I don't think I ever did get a price, so thanks to Don I now assume I saved about $50.
Cool.

[Don T]

Hello:
Frank C,
Factory recommended replacement varies but as I recall (it's been a few years) GM says 50,000 miles but most cars make 80,000 and some make it over 100,000. I know they try to time it just after warrantee expiration. O2 sensors however, start going "out of range" long before 100,000 miles.

[craiglaforce]

Gee, sounds like a job for a .45 V battery if there is such a thing.

[BK]

My 95 Toyota T-100 has 62,000 on it. I should mention that this model has 2 sensors. One for $187 and the other is $87. The rest of the $400 was for labor. Looks like I might have to replace if these sensors has a 80,000 life.