A/F Sensor Life

[artbuc]

Re my 99 Avalon V6, Ca Emissions. Replaced my Bank 1 A/F sensor at 80k. Now at 123k and it needs replacing again. My Bank 2 sensor is still original. It is a little lazy but still working. Just dumb luck or does Bank 1 (next to the firewall) fail more often? The replacement was Denso which should have been as good as OEM.

PS. This is really bizarre. I was thinking just a few days ago I should hook-up my scanner to see how she is running since I have not made any repairs or thrown a DTC in a long time. Driving home today the CE light came on. Go figure.

 

[hypervish]

That seems a little soon.

My original Bank 1 Sensor 1 didn't need to be replaced till 215,538 miles. The original Bank 2 Sensor 1 was replaced at 150,000 miles.

 

[slacktide_bitog]

I wouldn't be surprised if B1 sensors fail more often than B2 sensors. Too bad Bank 1 is the back!

Also surprising since Denso is the OEM for most Toyotas, including your Avalon.

And don't forget that the AF sensors they used in California emissions are different from the standard O2 used in federal cars.

You didn't drop it or anything, did you?

 

[Trav]

There is no concrete answer. Depending on how the engine ran during its life the sensor can go a couple of hundred thousand or 100K
If the engine ran with dirty injectors, higher misfire count (not enough to set a CEL) low quality oil the life could be significantly shortened.
Continued use of some chemicals or silicone sprays can cause an early demise also.

 

[Mr Nice]

120K max on my Hondas until a code is thrown.

 

[Superflan]

Ran original o2 sensors to 300000km on many euro cars. Only got one catback (check) sensor gone bad on Opel z22se. Front (pilot) sensor was still good at 232K

 

[artbuc]

Originally Posted By: slacktide_bitog
Too bad Bank 1 is the back!


Tell me about it! I have often said disconnecting the B1S1 connector was the hardest job I have done on this car, including TB and strut replacements.

 

[artbuc]

Originally Posted By: Trav
Depending on how the engine ran during its life the sensor can go a couple of hundred thousand or 100K. If the engine ran with dirty injectors, higher misfire count (not enough to set a CEL) low quality oil the life could be significantly shortened.Continued use of some chemicals or silicone sprays can cause an early demise also.


Don't think any of these apply, esp the oil. Even so, wouldn't these affect both upstream sensors?

 

[artbuc]

Originally Posted By: slacktide_bitog
You didn't drop it or anything, did you?


I don't think so but it was 7-8 years ago.

 

[Trav]

Originally Posted By: artbuc
Originally Posted By: Trav
Depending on how the engine ran during its life the sensor can go a couple of hundred thousand or 100K. If the engine ran with dirty injectors, higher misfire count (not enough to set a CEL) low quality oil the life could be significantly shortened.Continued use of some chemicals or silicone sprays can cause an early demise also.


Don't think any of these apply, esp the oil. Even so, wouldn't these affect both upstream sensors?


Not necessarily one plug on one bank with a slightly higher misfire count or a slightly dirty injector on one bank will just effect the bank its on.
Doing injectors its not at all unusual to find one that is off and its many times one at the beginning or end of the rail.

 

[artbuc]

Just checked it. Both sensor and heater circuits are open. Don't know why but this Denso is 100% kaput after 43k miles.

 

[Vikas]

Are you talking about the sensor or the wiring? The chances of a genuine Denso wideband going dead in 43K miles is very low. Those things are expensive!

 

[artbuc]

Originally Posted By: Vikas
Are you talking about the sensor or the wiring? The chances of a genuine Denso wideband going dead in 43K miles is very low. Those things are expensive!


Sensor. Delivered price including tax is $96. I also checked Bank 2 as a reference. Heater circuit was fine at 1.3 ohms and sensor circuit had continuity.

 

[GMBoy]

And don't forget that the AF sensors they used in California emissions are different from the standard O2 used in federal cars.

quote]


Not true. There are no "california" sensors. Most of the emmissions differences are in the convertor and programming. An O2 sensor only reads the oxygen content in the exhaust gas - it cannot do anything else.

 

[artbuc]

Originally Posted By: GMBoy

And don't forget that the AF sensors they used in California emissions are different from the standard O2 used in federal cars.

quote]


Not true. There are no "california" sensors. Most of the emmissions differences are in the convertor and programming. An O2 sensor only reads the oxygen content in the exhaust gas - it cannot do anything else.


He meant that Ca emission spec Toyota V6 use wide band A/F sensors instead of O2 sensors, upstream. Big difference in cost!

 

[GMBoy]

Originally Posted By: artbuc
Originally Posted By: GMBoy

And don't forget that the AF sensors they used in California emissions are different from the standard O2 used in federal cars.

quote]


Not true. There are no "california" sensors. Most of the emmissions differences are in the convertor and programming. An O2 sensor only reads the oxygen content in the exhaust gas - it cannot do anything else.


He meant that Ca emission spec Toyota V6 use wide band A/F sensors instead of O2 sensors, upstream. Big difference in cost!


Thanks for the clarification. We use wideband sensors on our GM products across the board. Didn't realize Toyota was different.

 

[artbuc]

Originally Posted By: GMBoy
Originally Posted By: artbuc
Originally Posted By: GMBoy

And don't forget that the AF sensors they used in California emissions are different from the standard O2 used in federal cars.

quote]


Not true. There are no "california" sensors. Most of the emmissions differences are in the convertor and programming. An O2 sensor only reads the oxygen content in the exhaust gas - it cannot do anything else.


He meant that Ca emission spec Toyota V6 use wide band A/F sensors instead of O2 sensors, upstream. Big difference in cost!


Thanks for the clarification. We use wideband sensors on our GM products across the board. Didn't realize Toyota was different.


I think they are different only on the older models. I believe "modern" Toyota V6's use wideband sensors upstream. Eg, Avalon's went wideband in 2000 and Camry went a couple years later.