Used OEM O2 Sensor $25 or new pepboys part $75?

Can you buy both of them and then decide? I'm sure many of us would want to know what option is best... Hopefully someone else will chime in. My hunch is that an 02sensor either works or doesn't work and there's not an issue of anything getting worn out. But I don't know what it is specifically that causes an 02sensor to fail.

 

You get what you pay for. If you don't want a Toyota branded product, you can buy the Denso brand, which makes the Toyota stuff.

Most electronic parts can't be returned so it's best you don't buy generic and find out it doesn't work or it'll fail prematurely

 

I'm (purely) guessing an O2 sensor slowly gets a coating, carbon or whatever. I would get new. Then the question: is there really any difference between the part Pep Boys sources and the one you buy at a dealership parts department? Research it.

 

The choice of original or aftermarket parts is about both quality and compatibility. Toyota generally doesn’t publish engineering documentation for parts, and if you buy a part offered as a substitute, it may or may not have all of the important characteristics of the original, some of which may not be obvious.

Toyota’s heated oxygen sensor (89465-47070, according to the parts catalog) comes with an electrical connector and grommet, seen in many photos. If I were shopping for an aftermarket replacement, before I’d buy a generic one, I’d consider the Denso 234-4623, which, at this writing, Pep Boys sells online for $37.80. It gets favorable Amazon.com reviews from owners of second-generation Prius cars, so the compatibility seems clear: indeed, as @JC91006 notes, Denso was the original supplier to Toyota.

Toyota’s technical training (T874) says, “Contamination or corrosion of the platinum electrodes or zirconia elements will reduce the voltage signal output.” I suppose damage to the wiring or connector or burnout of the heater circuit are also possible failure modes.

 

On a lot of Toyota parts they just grind off the Toyota name and sell it under their own name. Asin water pumps do that all the time. The Asin clutch I replaced on my 4 Runner was the exact same clutch Toyota sells. That Denso O2 sensor is probably OEM.

 

I think it is fine to buy replacement parts from sources such as Aisin and Denso as they are the original equipment suppliers used by Toyota. I would not buy no-name aftermarket parts.

I hope the OP recognizes that the upstream sensor is an air/fuel ratio sensor while the downstream sensor is an O2 sensor. Big difference between the two with regards to voltage output and behavior.

I would not install a used sensor unless it is known to come from a low-odometer reading vehicle.