Replace oxygen sensor by mileage ?
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I only replace them when the relevant CEL code pops up, or upon replacing the cat
My previous LS400 still had original front O2 sensors when I sold it few months ago after 22 years and 380k miles. The rear O2 sensors had been replace once.
I replaced my Jeep's @110k. Made a marked difference in power and economy .never threw any codes with the old ones.
Originally Posted By: Chris142
I replaced my Jeep's @110k. Made a marked difference in power and economy .never threw any codes with the old ones.
Interesting. I replaced the ones in my Sienna at about 300,000 miles, mostly just because it hadn't ever been done and I had the intake plenum off which made easy access to the connectors. I didn't notice a thing and fuel economy didn't change a bit. I guess I was expecting something but apparently I should have just left the old ones installed.
Ditto for the BMW, those had less miles but were 22 years old. No discernable difference, at least not yet.
I replaced my Jeep's @110k. Made a marked difference in power and economy .never threw any codes with the old ones.
Interesting. I replaced the ones in my Sienna at about 300,000 miles, mostly just because it hadn't ever been done and I had the intake plenum off which made easy access to the connectors. I didn't notice a thing and fuel economy didn't change a bit. I guess I was expecting something but apparently I should have just left the old ones installed.
Ditto for the BMW, those had less miles but were 22 years old. No discernable difference, at least not yet.
I always wondered this, glad I saw this post & feedback.
Due to cost, I usually wait till I see a sign of failure (CEL primarily). I think modern fuel injection (the computer) is a lot better at narrowing things down than it was 15+ years ago. I used to hear the recommendation that you should replace them every 50k, but that was years ago and coming from auto parts stores and mechanics.
FWIW, the rear sensor simply monitors emissions performance (what's coming out after the cat) and has little or nothing to do with how the ECU/EFI behaves. The upstream sensor on the other hand, directly tells the ECU whether the mixture is rich or lean--- I would replace the upstream sensors first, if I felt I needed to include oxygen sensors as part of preventative maintenance.
Due to cost, I usually wait till I see a sign of failure (CEL primarily). I think modern fuel injection (the computer) is a lot better at narrowing things down than it was 15+ years ago. I used to hear the recommendation that you should replace them every 50k, but that was years ago and coming from auto parts stores and mechanics.
FWIW, the rear sensor simply monitors emissions performance (what's coming out after the cat) and has little or nothing to do with how the ECU/EFI behaves. The upstream sensor on the other hand, directly tells the ECU whether the mixture is rich or lean--- I would replace the upstream sensors first, if I felt I needed to include oxygen sensors as part of preventative maintenance.
If it isn't heated, maybe. If it is heated, no.
Originally Posted By: 92saturnsl2
I always wondered this, glad I saw this post & feedback.
Due to cost, I usually wait till I see a sign of failure (CEL primarily). I think modern fuel injection (the computer) is a lot better at narrowing things down than it was 15+ years ago. I used to hear the recommendation that you should replace them every 50k, but that was years ago and coming from auto parts stores and mechanics.
FWIW, the rear sensor simply monitors emissions performance (what's coming out after the cat) and has little or nothing to do with how the ECU/EFI behaves. The upstream sensor on the other hand, directly tells the ECU whether the mixture is rich or lean--- I would replace the upstream sensors first, if I felt I needed to include oxygen sensors as part of preventative maintenance.
I really would prefer to catch it before it causes a misfire so that I can avoid contaminating the catalytic converter with a rich condition.
I'd only have to replace the upstream sensor for the reasons you mentioned. My Buick only has two oxygen sensors, which makes it a lot more economical to replace than some of the other cars that have four oxygen sensors.
I always wondered this, glad I saw this post & feedback.
Due to cost, I usually wait till I see a sign of failure (CEL primarily). I think modern fuel injection (the computer) is a lot better at narrowing things down than it was 15+ years ago. I used to hear the recommendation that you should replace them every 50k, but that was years ago and coming from auto parts stores and mechanics.
FWIW, the rear sensor simply monitors emissions performance (what's coming out after the cat) and has little or nothing to do with how the ECU/EFI behaves. The upstream sensor on the other hand, directly tells the ECU whether the mixture is rich or lean--- I would replace the upstream sensors first, if I felt I needed to include oxygen sensors as part of preventative maintenance.
I really would prefer to catch it before it causes a misfire so that I can avoid contaminating the catalytic converter with a rich condition.
I'd only have to replace the upstream sensor for the reasons you mentioned. My Buick only has two oxygen sensors, which makes it a lot more economical to replace than some of the other cars that have four oxygen sensors.
Yes, replace them when they throw the code. A additional 1MPG is observed after replacing it w/ a new one but you will loose the gain a yr.
And those dammam sensors don't come cheap!!
And those dammam sensors don't come cheap!!
Yeah, I'll go with slacktide_birogs advice as at my work being a mechanic; I would be fired for changing parts when I felt like it. Costs time and$$$
I always wait until I have a code. Right now I have a Bosch on my 1995 Escort that has almost 150K miles on it and it seems to be working fine.
Originally Posted By: MaximaGuy
Yes, replace them when they throw the code. A additional 1MPG is observed after replacing it w/ a new one but you will loose the gain a yr.
And those dammam sensors don't come cheap!!
The prices of an O2 sensor depends on the car. On many GM 4-cylinder engines, $65-$75 is what you usually pay.
However, ones for Lexus models are usually very expensive. I remember when my dad had an ES300, the price was $200 per sensor.
Yes, replace them when they throw the code. A additional 1MPG is observed after replacing it w/ a new one but you will loose the gain a yr.
And those dammam sensors don't come cheap!!
The prices of an O2 sensor depends on the car. On many GM 4-cylinder engines, $65-$75 is what you usually pay.
However, ones for Lexus models are usually very expensive. I remember when my dad had an ES300, the price was $200 per sensor.
There are many factors that affect sensor life.
They can vary greatly between individual vehicles.
Oil composition and consumption, driving conditions etc.
I'd check the sensor waveform periodically with a scope or scanner, rather than replace on a schedule.
They can vary greatly between individual vehicles.
Oil composition and consumption, driving conditions etc.
I'd check the sensor waveform periodically with a scope or scanner, rather than replace on a schedule.
If my gas mileage is very consistent, the car drives the same & no codes, nothing to do. I track every fill up & put it in Excel every blue moon.
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