I used to replace o2 sensors as a maintenance item every 80k or so, but that was when they were $30 and I could read the performance on the dash CRT. Not any more though.
Just curious, what kind of car had a CRT on the dash?
I had a Plymouth Minivan we took on an 8700 mile trip and the gas mileage gradually dropped from 20+ to 12 mpg. At midpoint on the trip I even jacked up and spun all 4 wheels looking for a cause. Two weeks after I got back the check engine light came on with the code for the oxygen sensor.
Replaced it and back up to 20.
@db4690, you’re correct. That was in the late 70s and early 80s. SAAB and VW first started using O2 sensors in 1977; long before almost all other car makers did.
My assumption, right or wrong, is that other Euro cars may have done the same thing.
When a SAAB actually needed an O2 sensor it was usually because someone had not used extreme care when servicing or replacing the battery which was located next to the O2 and required finesse to R & R.
One bump from the battery and the O2 was junk.
I remember a Benz where to replace the sensor, you had to lift up the passenger side carpet, because the connector was inside the vehicle
On some Camry’s, you have to lift the carpet up behind the drivers seat to gain access to the connector to the post cat O2 sensor.
Tester
Was it Volvo that had the ‘Lambda’ sensor?
A lambda sensor is the same thing as an O2 sensor.
Tester
Yeah, I think Volvo named in ‘Lambda’ in 1976, first sensor for 3-way cats.
I’ve never replaced a sensor, and have driven cars well past 300,000 miles. Sensors fit in the “run to failure” category, and are replaced when they fail.
Because they are so reliable and long lived now it makes no sense to replace them pro-actively.
I have found that O2 sensors begin to fail somewhere around 110,000 miles. You guys that live down the street from an Autozone, drive until they fail, no sweat. For those of us who live hours away from any possible source of parts, need to have a different approach.
My 2002 Sienna which is soon going to be illegal in Mexico, for a long time had intermittent CAT efficiency failures. At around 110,000 miles (on the sensor, not car miles), one of the sensors failed its heater on a cross country trip. Since it was only the heater, I drove it the 1200 miles home and had it replaced.
Last October, my Son-in-law agreed to replace the other two, using Denso parts from Rock Auto, though they showed no failure as such. Voila! No more P0420 failures.
I make no secret of having great respect for Docnick, and have said so. But, this is one place I cannot totally agree with him.
In my extensive Internet searches for this topic, I found many mechanics who state that sensors may well deteriorate, though there is no CEL code. Since my experience agrees with them, I take their word on it.
My 2002 Sienna which is soon going to be illegal in Mexico
Just curious @irlandes why? What’s the Mexican gov’ts motivation to make that vehicle illegal? Does this ban affect vehicles already on the road in Mexico like yours, or just ones driven or imported into Mexico in the future?
@“oldtimer 11” the Buick rivieras and olds toros had the CRT screen from 86 to about 94. If you knew what buttons to push from the service manual, you could go into diagnostics while driving and see all of the obd1 readings.