O2 sensor a maintenance item?

[Donald]

Originally Posted By: Trav
Yes i let them go to about 100-125K then swap the upstream out. The older the downstream is and still functioning the better it is at keeping pesky P420/P430 away.

The injectors in those engines were reliable enough they just didn't atomize very well.
The single stream in a 2V head is fine, they can however cause cylinder wall wash down when one goes a little lean (dirty) and the PCM fattens the rest up attempting to maintain stoichiometric.

As someone posted there are better more modern alternatives as far as injectors go, they are not very expensive.


What injectors would you suggest?

 

[Chris142]

I replaced my jeeps. @110k due to them being lazy. No codes ever popped up. Power and economy both improved . I went with Bosch first and they threw codes so I had to get the dealer ones

 

[Trav]

Originally Posted By: Donald
Originally Posted By: Trav
Yes i let them go to about 100-125K then swap the upstream out. The older the downstream is and still functioning the better it is at keeping pesky P420/P430 away.

The injectors in those engines were reliable enough they just didn't atomize very well.
The single stream in a 2V head is fine, they can however cause cylinder wall wash down when one goes a little lean (dirty) and the PCM fattens the rest up attempting to maintain stoichiometric.

As someone posted there are better more modern alternatives as far as injectors go, they are not very expensive.


What injectors would you suggest?


A Bosch III stainless steel core injector would work very well, they are ethanol compatible also.
Plug and play.

 

[PandaBear]

I never see an mpg increase, but I usually only replace it if I'm about to fail smog check with high HC / CO and Nox.

 

[zrxkawboy]

I typically replace the upstream sensor(s) around 100k. Sometimes I see a mpg improvement, sometimes not. I always purchase the brand of sensor that was OEM.

 

[artificialist]

Originally Posted By: eljefino
My mom's 1981 dodge omni miser did not have a check engine light.

However, it had an "o2 sensor" light that lit at, IIRC, 60k to remind the driver it was time for its regular service.

Nissan did that back in the 1980s as well.

Anyway, the reason they did that is because an O2 sensor tends to react more slowly with age. Early engine management systems wouldn't detect that, and the only thing that would cause an O2S error code is an open circuit, a short circuit, or a voltage higher than 1V. Most of those sensors had no heaters, but if a short or open circuit was detected in the heater, that would cause an error code.

OBDII engines are said to detect slower reactions of oxygen sensors, but it isn't perfect. That is why some call it a maintenance item.

My dad once had a Lexus ES300 which reached the point the O2S needed replacement, but back then, we could only find matching sensors at $300 per bank. Back when gasoline was $150 a gallon, losing 1 MPG wasn't so bad.

 

[InvalidUserID]

I've replaced them on my cars when emissions numbers get much worse, a CEL, or a high mileage amount.

Never seen a noticeable MPG gain but have seen lower emission numbers and a little more "kick".

 

[hsd]

Replaced upstream sensor with new Denso on my 2000 Accord at 140k miles, no code showing. Mpg was 0.5 mpg higher over next 3000 highway miles, but thats within normal mileage variation, so no real improvement.

 

[TFB1]

o2 sensors can and do get lazy... Usually this happens by 125-150K mi and result is generally decreasing fuel mileage...

Have I ever replaced a high mileage o2? Nope not unless it was setting a cel...