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.
Quality Tested - built to a strict level of product standards.
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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Expedited is available on checkout to the United States, excluding Alaska, Hawaii and US Territories as well as P.O. Boxes and APO/FPO/DPO addresses. Final shipping costs are available at checkout.
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.
OSA61272
In Stock
Product Reviews
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4.67/ 5.09
9 reviews
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Incorrect length for 05' Pontiac Vibe
A
July 9, 2018
I was able to install this replacement O2 sensor, and it functions as it should. The installation was mostly free of problems, as the threads and plastic plug fit well. Unfortunately, the rubber plug/seal isn't located in the correct spot on the wires, and it's permanently affixed. It's about 1.5 inches too close to the square plug, leaving the wires too short inside the car, and a bit too long under the car. I was able to make it work by disconnecting the square plug base from under the dash, but now that kind of flops around up there. The loop under the car is also a bit longer than needed, increasing the likelihood of catching on grass, sticks, debris, etc. Overall the product functions, it's just a little annoying when there are only a couple things to get right on a piece like this... or get wrong. I suppose I'd buy the part again seeing as it's less than half the cost of a factory replacement, but I advise buyers to manage their expectations prior to purchasing.
Works; Fits; Not much more to say
J
July 10, 2019
Build quality seems identical to original equipment. Connectors/seals all fit. Emission monitors set after installation and could see electrical variation in line with expected values and waveform shape.
Gasket in wrong location
M
August 6, 2019
The sensor worked great. The only issue is that on my 2006 Toyota Corolla the gasket was in the wrong location. The gasket would need to be cut and moved to the correct spot. A very small issue for such a great part. No issues otherwise.
Perfect
William
February 6, 2020
Great product and perfect fit .. easy to order
CARLOS
August 8, 2021
o2 sensor fit perfectly exating what I ordered.
THE BEST parts and service !
Cheryl
January 21, 2022
Wonderful service with the PERFECT part !
Good product
Eulogio
September 23, 2023
Working great.
Dale
April 4, 2024
Works great
Good
Luis
June 13, 2024
I've noticed a small difference in performance and fuel economy my car rides smooth now and the rough idling went away!
Customer Q&A
it says downstream for 2005 toyota matrix 2zz ge engine why does it look different from the one my car has? does it matter will it still work?October 9, 2021
Ronaldo R
10
My car is California compliant, so it could be different
October 9, 2021
G A
10
Mine did not fit, the threads did not match the original.
October 9, 2021
B W
10
The threads did not match the factory sensor threads for my 2004 Toyota Corolla. I ate the cost of the sensors.
October 9, 2021
B W
10
This part will fit:
2003-2006 Toyota Matrix L4 1.8L Front Wheel Drive
2003-2006 Toyota Matrix XRS L4 1.8L (Engine ID 2ZZGE)
October 9, 2021
Cristina P
Customer service
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