OK, Lets Talk About Oxygen Sensors

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Jun 23, 2024
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OK, Lets Talk About Oxygen Sensors

First, DO NOT PURCHASE oxygen sensors off eBay or Amazon, those venues are flooded with counterfeit oxygen sensors, you’re just wasting your time and money.

You need to verify the specifications of the oxygen sensor(s) when you receive them from the supply source to be sure they‘re good before installing them. One of the easiest tests that you can perform is with a simple multi-meter. This requires that you connect your multi-meter probes across the heater circuit and to make sure it meets the required resistance specifications based on the make and model year of the vehicle.

How do you know what to look for, well for instance, GM ACDelco has a Facts About Oxgen Sensors PDF document that you can download and print. This chart will tell you what oxygen sensor heater resistance to look for based on the make model and year of vehicle, simply type the following into your browser, it‘s called:

The Facts About Oxygen Sensors

This will get you there so you can download the document. Note this is for GM vehicles, you can find information for other makes on the Internet.

The second piece of information you will need is a document that will tell you the wiring color code chart for oxygen sensor(s), you can find that here, the document is made available by HIFLOW:

https://www.academia.edu/5496281/O2...from_http_www_hiflo_com_au_oxygen_sensors_cfm

you can download the document in PDF format which will provide you with the wiring color codes for various brands of oxygen sensors so you can test them with a simple multi-meter whether 1, 2, 3, or 4 wire.

Next, I would recommend using Denso oxygen sensors, I’ve yet to get a bad one, they are a high quality product. Also make sure that the item is in the original manufacturers packaging (box), in a sealed bag, including a product label and bar code. Denso oxygen sensors are assembled in the USA and mine come out of San Bernardino, California (Long Beach, CA).

I’ve tested a substantial number of so-called “NEW Out Of The Box” oxygen sensors over the years that folks purchased off eBay and Amazon, they were absolute “JUNK, NO GOOD”. If you’re looking for a reliable auto parts source I would recommend RockAuto, I’ve purchased parts from them for many years and never received a defective item, or one that didn’t meet OE specifications (note I don’t receive any compensation from RockAuto for my recommendations). RockAuto shipping costs are a bit more expensive, however, they deliver on time, most often sooner than expected, and the product is well packaged. They are tested before shipment, I’ve never received a bad one.

Regardless of the brand of oxygen sensor you purchase DO NOT PURCHASE THEM OFF EBAY OR AMAZON, you will stand a very good chance that they will be counterfeits, or will fail in the short term.

Lastly, I would highly suggest that you use a fuel system cleaner, there are a variety of them available at auto parts stores, however, just like oxygen sensors you have to chose wisely, if you want the best that’s really effective, not just a bunch of advertised hype, I would suggest that you purchase Red Line Sl1 Fuel System Cleaner. It costs around $15.99 but this stuff really works and contains the highest percentage of PEA (Polyetheramine), 30-50%, P.E.A. is a nitrogen-based detergent stable enough to survive the harsh conditions of a combustion chamber. It is the most potent detergent available for cleaning carbon deposits in fuel systems and the only cleaning agent that has been proven to clean the combustion chamber, piston tops and cylinder heads.

Hope this information helps.
 
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RockAuto closeout / house brand that are sourced from the same manufacturer my car come with is my go to. I usually only buy a new one if my car is slightly failing smog, and my main concern is a different manufacturer will have a different calibration than my existing one and tip the reading off slightly, and get me a slightly worse smog result. Same manufacturers have a higher chance of getting the same calibration as OEM and pass better.
 
Or the NGK store?

you wouldnt think they'd be counter fit, ive used them and they performed as well as original and the same life span.
A lot of the sensors are sold with just wire and no connector, and you have to crimp them or solder them yourself.

I would imagine if someone buy those loose sensors and crimp connectors themselves, they would not be genuine like the one you buy directly from Denso, Bosch, or NGK, even if the sensors are the same. That doesn't mean they are not fake, and that also doesn't mean they won't perform identical. I typically buy those on RockAuto and had no problem with them.
 
I've had decent luck with universal, splice type sensors. Since the physics are the same, the difference, IMO, is build quality and an intellectual property premium for the vehicle specific electrical connection.
 
A lot of the sensors are sold with just wire and no connector, and you have to crimp them or solder them yourself.

I would imagine if someone buy those loose sensors and crimp connectors themselves, they would not be genuine like the one you buy directly from Denso, Bosch, or NGK, even if the sensors are the same. That doesn't mean they are not fake, and that also doesn't mean they won't perform identical. I typically buy those on RockAuto and had no problem with them.
Never solder O2 sensor wires, the sensor "breathes" air through the wires.
 
Never solder O2 sensor wires, the sensor "breathes" air through the wires.
The wire pigtail was really long so you are probably going to solder 8" away from the sensor. I never soldered either and just buy pre-crimped 3rd party sensor that buy sensors from NTK / Denso / Bosch.
 
The wire pigtail was really long so you are probably going to solder 8" away from the sensor. I never soldered either and just buy pre-crimped 3rd party sensor that buy sensors from NTK / Denso / Bosch.
First gen sensors had a hole in the body, later more modern ones get a very small amount of air in the connector through the wires, they cannot be soldered at any length.
 
There are legit sources for O2 sensors on eBay and Amazon. It takes a little homework. I have purchased them from car dealers with an online presence I could confirm...they simply had an eBay account/store as well. I have also found a few reputable eBay sellers that are legit.
German Auto Supply
https://www.ebay.com/str/germanautosupply

Parts Container
https://www.ebay.com/str/partscontainer?_trkparms=folent:partscontainer|folenttp:1&_trksid=p3542580.m47492.l74602

I have only received legit Bosch, NGK, and other european parts for my cars.
 
Never solder O2 sensor wires, the sensor "breathes" air through the wires.
Yea, Bosch say not to do that with theirs, they use a design that uses the sensor wires for their reference air source. Bosch does include Weather-Tite solderless connectors and a shell to secure the splice with their universal sensors. A tiny bit of air can enter through the splice, using solder can wick down to the sensor.

Denso and NTK(soon to be one) use the sensor body’s hole to get its reference air through a PTFE filter.
 
Ok that makes sense then. The only car I had that uses Bosch was worn out for other reason and never lived to an old age that needs a new O2. The ones that aged into 20+ years were using NTK and Denso.
 
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