TRQ oxygen sensors are manufactured to precise specifications using premium raw materials to optimize your vehicle’s emission system. Each sensor is isostatically-pressed for improved strength and durability, and plasma-sprayed to improve sensitivity and prolong the service life of the sensors. Oxygen sensors wear out over time and should be replaced every 60,000 miles to prevent poor engine performance. TRQ recommends replacing the oxygen sensors in sets to optimize fuel economy and reduce overall emissions. All products are fit and road-tested in our Massachusetts R&D facility to ensure we deliver on our promise of Trusted Reliable Quality.
Product Features
Application Specific Design: No modifications and pre-calibrated
Isotatic-pressed and plasma-sprayed for extended service life
Double-Layered 310S Stainless Steel: Additional protection from moisture and debris
Restored Engine Performance: Improved fuel economy and lower emissions
What is Upstream vs. Downstream?
Upstream location is between the catalytic converter and the engine
Downstream location is between the catalytic converter and the tailpipe
Install Tip: You may be required to reset the vehicle computer after installation of this part.
Item Condition:New
Attention California Customers:
WARNING: This product can expose you to chemicals including Lead and Lead Compounds, which are known to the State of California to cause cancer, and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Lifetime Warranty
This item is backed by our limited lifetime warranty. In the event that this item should fail due to manufacturing defects during intended use, we will replace the part free of charge. This warranty covers the cost of the part only.
Returns: Parts with electrical components cannot be returned once installed.
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O2 Sensors is it Upstream or Downstream
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1. Identifying your Oxygen Sensors
Upstream oxygen sensors are located in between the engine and the catalytic converter
Downstream oxygen sensors are located in the catalytic converter or farther away from the engine than the catalytic converter
Locate your vehicle's firing order diagram
The bank that contains cylinder one is bank one
The bank that does not contain cylinder one is bank two, even if it does not contain cylinder two
Hi, I'm Mike from 1A Auto. We've been selling auto parts for over 30 years. We're dedicated to delivering quality auto parts, expert customer service, fast and free shipping, all backed by our 100% satisfaction guarantee. Visit us at 1AAuto.com, your trusted source for quality auto parts.
In this video I have a couple of oxygen sensors with me. While there are some aesthetic differences here, the wire lengths are a little different, the actual body and tip of the sensor are a little different, the threads and gasket are the same, and on the other end the connections are actually the same. I can plug these into either position on our vehicle. But if I had to ask you which one's upstream and which one's downstream, you probably can't tell just from looking at them. That's true of most oxygen sensors. The way you determine whether or not an O2 sensor is upstream or downstream is all done visually.
Your oxygen sensor position can be determined relative to your catalytic convertor. As the name suggests, upstream sensors will be located upstream or ahead of, in front of, above, closer to the engine than your catalytic convertors. This means that they see the exhaust gasses first. They then go through the catalytic convertor and to the downstream oxygen sensor, which will either be located in the catalytic convertor like our vehicle here, or after the catalytic convertor to monitor the gasses coming out of the cat and make sure that it's being efficient relative to the readings of the upstream O2 sensor.
The other determination you need to make is bank one versus bank two. Determining which bank is which can be done by looking at a picture of your vehicle's firing order. Whichever bank contains cylinder one is going to be bank one, and the other one, regardless of whether or not cylinder two is in it, is going to be bank two by default. These banks are true of V engines like V8s, V6s, and flat engines like Porsches and Subarus that have individual banks.
On inline four-cylinder engines, as long as they have one exhaust manifold like a Jeep four-liter or a four-cylinder Honda engine, you'll only have one bank with an upstream and downstream O2 sensor. There will be no bank two on the engine.
On our vehicle here, this is the passenger side, which we've already determined from the firing order is bank one. We have our upstream sensor here closest to the engine ahead of the cat. Then we have our downstream or sensor two here inside of the catalytic convertor. This could also be located somewhere after the cat. Here I have my two sensors for the vehicle. While they are aesthetically different, we can now tell this is my upstream sensor because it looks just like the upstream sensor I have up there. This is my downstream sensor. Now that we know which one's which, we can order the right part, correct the problem, and fix you up right.
Thanks for watching. Visit us at 1AAuto.com for quality auto parts, fast and free shipping, and the best customer service in the industry.
OSA61215
In Stock
Product Reviews
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3.88/ 5.08
8 reviews
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Awesome
Terry
April 22, 2017
Excellent price and self help video, 5 star stellar.
O2 Sensor
Alan
August 6, 2018
I installed the O2 sensor I ordered from A1 Auto and evrerything was perfect. The plug was an exact fit and it came with anti seize already on the threads. Best of all it got rid of my engine code.
Easy... install
M
April 10, 2019
Came with sealer. No cutting required. A zip tie on one. Code light went out with a little driving around. No problem...
Fit was good works fine. There was a small problem
M
August 10, 2019
The sensor fit great and had no problem installing it. There was a small issue that is not a show stopper.
When installed on bank 2 of my 2011 GMC 2500HD, the wiring connector is closer to the sensor than on bank 1 creating excess wire length. Finding a way to keep the sensor wire from hanging down on either the catalytic converters or the front drive shaft was annoying. I ended up doing a temporary solution until I come up with a permanent one.
Otherwise all good.
The right part the first time.
S
December 3, 2019
I ordered these for my 2011 Camaro SS. They were a perfect direct replacement. Ordering and receiving my parts was fast and easy, will definitely be ordering from these guys again!!!
Sent wrong part
C
June 28, 2020
Wrong part not good need to return?
Possible faulty
T
August 9, 2020
Parts Installed easily. But problem still persists. I love 1A auto. But Im kinda disappointed in these parts.
Worked well
Jacob
January 6, 2021
Fit perfect and went right in! No complaints here.
Customer Q&A
Is this the upstream sensor for both sides?August 17, 2018
G U
10
This part is listed as Upstream or Downstream Sensor as listed per applications. Plase check the vehicle fit list or provided your vehicle year, make and model so we can assist you.
August 17, 2018
Elesban A
10
Yeah, they are the same on both sides upstream. Just watch for the connection to the wiring harness to be right for your model. Either oval connector or rectangular.
August 17, 2018
Kyle K
Does this come with both sides or is the price just for one?June 8, 2020
Zach L
10
This will come as one part as pictured. Please do not hesitate to contact us with any further questions.
June 8, 2020
Emma F
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