★★★★★
April 25, 2026
Perfect replacement parts
TRQ parts are first quality and always work
Replaces
Part Details
Specifications
About TRQ:
TRQ is a trusted brand dedicated to making every repair a success story by combining premium parts with easy installation. Each TRQ part is engineered by a team of automotive experts to meet or exceed OEM standards, delivering enhanced performance and maximum longevity. With rigorous in-house testing, the brand ensures superior fit and function across every product line. TRQ also provides customers with best-in-class, step-by-step installation videos—so you can complete repairs with confidence, whether you're a first-time DIYer or an industry professional.
Product Features
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.
What is Upstream vs. Downstream?
Install Tip: You may be required to reset the vehicle computer after installation of this part.
Returns: Parts with electrical components cannot be returned once installed.
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.
FREE Shipping is standard on Orders shipped to the lower 48 States (Contiguous United States). Standard shipping charges apply to Hawaii, Alaska and US Territories. Shipping is not available to Canada.
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.
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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.
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Hi, I'm Mike from 1A Auto. I hope this how-to video helps you out, and next time you need parts for your vehicle, think of 1AAuto.com. Thanks.
In this video, we're going to show you oxygen sensor replacement. This is the rear oxygen sensor on this 2003 Honda Civic. The only items you'll need include a new oxygen sensor from 1AAuto.com, and we also sell the oxygen sensor socket.
Raise and support your vehicle.
Then locate your oxygen sensor in the center of the rear cat converter. Locate the connector for your oxygen sensor on the passenger side of the firewall, just above the subframe. Release the retainer and disconnect it. Remove it from the retaining clip and let it hang. To remove the oxygen sensor, we'll be using this oxygen sensor socket from 1AAuto.com. You can see here that it has a small window cut out of one side of the socket that allows for the sensor wiring to rotate around without being crushed, pinched, or otherwise damaged in the 6-point socket. It uses the standard 3/8ths drive, or you can put a bigger socket on with a 1/2" drive for a little more torque.
Here we have our old oxygen sensor from our vehicle, and our new one from 1AAuto.com. As you can see, we have the exact same threads in sensor. Our new one actually comes with a little bit. Never Seez on it to keep it from getting stuck in the catalytic converter. We have the same 4-pin connector, and the same rubber boot to attach into the retainer on the firewall. This is going to go right in, direct fit.
Here's our new sensor from 1AAuto.com. We'll go ahead and start those threads into the cat converter by hand. Bring it down the rest of the way with our sensor socket. Be sure, especially when installing the new sensor that the wire can rotate freely, so it doesn't get pinched, twisted, or otherwise damaged during installation. Torque the sensor to 33 foot-pounds.
Reinstall your O2 sensor connector at the firewall. Be sure that it clicks, then install into the retainer. Be sure to leave a little bit slack on both ends of the line.
Thanks for tuning in. We hope this video helped you out. Next time you need parts for your car, please visit 1AAuto.com. Also check out our other helpful how-to and diagnosis videos.
OSA61199
TRQ parts are first quality and always work
Good quality product, delivered timely, affordable price.
Compre este sensor para mi Honda Civic 2005 ex y funciono perfecto y se le quito el error relacionado con ese sensor.
First time Ive purchased with this site/company. Very satisfied!
It came with anti Seize on the o2 sensor which was awesome
Item ship as promise.
I order from 1 a auto all the time I go there first before I go anywhere else Parts always Fits right no problems here an will continue to shop and recomed to friends...
The part fit exactly as needed and the ordering was easy!
Installation was almost as easy as in the video - the only difference was mine was stuck in there and it took a lot more effort (until I used penetrating oil). Check Engine light is out and the van runs great!
This O2 sensor works with my Honda Civic 2004 EX. I have check engine light P0139 and P0404. Had hard time removing O2 sensor. Decided to bring my car to Velasquez muffler and brakes. They replaced the O2 nut for $45 fee. Drove for 75 miles then went for emission test. All tests PASSED. Thank you 1A Auto.
It works well for my early 2000s Honda Civic, which is a car that has low emissions tolerance.
This part will not fit your vehicle, but we may have a part that is listed to fit. Please enter your vehicle's year make and model in the search bar at the top of the page. This will display parts guaranteed to fit your vehicle. Just be sure to verify all of the information shown in the Vehicle Fit tab before ordering.
Do Not speak Spanish never mind read it
There is not carb specification that needs to be met with this part.
This part will not fit your vehicle, but we may have a part that is listed to fit. Be sure to verify all of the information shown in the Vehicle Fit tab before ordering.
This part will not fit your vehicle. We may have a part that is listed to fit. Please enter your vehicle's year make and model in the search bar at the top of the page. This will display parts guaranteed to fit your vehicle.
What is your year and model so we may confirm fitment?
No this does not fit the DX sedan.
