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
How to Replace O2 Sensor 2001-05 Honda Civic
Created on:
Tools used
No Tools Needed
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.
Tools used
Socket Extensions
O2 Sensor Socket
Jack Stands
Ratchet
Floor Jack
1. Removing the Oxygen (O2) Sensor
Raise and secure the vehicle
Disconnect the oxygen sensor wiring harness
Remove the O2 sensor with an O2 sensor socket and a ratchet
2. Installing the New O2 Sensor
Twist the new O2 sensor into place
Tighten the O2 sensor with an O2 sensor socket and a ratchet
Connect the O2 sensor wiring harness
Lower the vehicle to the ground
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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.
OSA61675
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3.75/ 5.04
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Oxygen sensor pair
A
November 2, 2018
Price was great , came fast was great Ill be ordering from you again
1aauto feedback
Munga
January 1, 2019
I'm relatively new to the website but I'm enjoying receiving the right parts every time I place an order. I also enjoy the prompt timing I receive the packages. Thank you
Worked great
K
February 27, 2019
Worked in my 2005 Honda Civic ex coupe
francisco
April 3, 2024
didn't work the check engine light came back with the same code.
Customer Q&A
Will this work with engine designation d17a2?August 12, 2018
GLENN Z
10
Thank you for reaching out to us. I do see that these will fit the 1.7L from 2001-2005. Just make sure that the plug styles do match coming from the car to the O2 sensors. If you have any other questions feel free to contact us and have a great day!
Thank you!
August 13, 2018
Corey M
Hello. Does this fit the 2002 Honda Civic LX 1.7 MT D17A1?December 20, 2018
C E
10
Currently we do not carry this part for your vehicle. We're always updating our inventory so please check back soon! If you have any other questions, let us know.
December 20, 2018
Christa R
I bought these sensors for my 05 Honda Civic, 2 arrived looking basically identical. One is marked YX1712011, the other one is marked YX1810141. Which is Upstream and which is Downstream? They look almost identical.March 8, 2019
Emil A
10
According to the specifications on the individual parts, they can function as an upstream or a downstream sensor depending on the vehicle they are installed on to. If you'd like to contact our Customer Service department we will be happy to help verify which 1A part number is which for you.
March 8, 2019
Peter L
Will this fit a 2005 Honda Civic LX Special Edition, it's also 1.7?April 22, 2019
Jenny C
10
These oxygen sensors will not be correct for the 2005 Honda Civic LX. The part number that you would need for your vehicle is 1AEEK00173.
April 22, 2019
Preston C
Will this fit a 2004 civic ex vtec?July 7, 2019
Braden A
10
This is not listed to fit a 2004.
July 7, 2019
Andra M
Does it work on 2002 civic ex model?October 18, 2019
Tim H
10
I bought them for my 2005 hinda civic ex and the upstream sensor still throws a code after install. I had to buy by a oem for it to stop the rear downstream sensor did work fine
October 18, 2019
Joshua G
10
Thanks for contacting us. This part is listed to fit the following:
2001-2003 Honda Civic EX L4 1.7L Upstream & Downstream O2 Oxygen Sensor Pair
Please let us know if we can be of any further assistance and we will be happy to help.
October 19, 2019
Peter L
I see this fits the EX, will it also fit the LX?March 13, 2020
WAYNE T
10
Thank you for your inquiry! This kit is not listed to be compatible with the LX model. In order to confirm if we have the correct oxygen sensors for you please feel free to contact back with your 17-digit VIN so we can review our inventory. We look forward to hearing back from you!
March 13, 2020
Jessica D
Customer service
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