Install Tip: You may be required to reset the vehicle computer after installation of this part.
Direct Fit Replacement - Guaranteed to fit and function for your specific application 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 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.
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O2 Sensors is it Upstream or Downstream
How to Replace Downstream O2 Sensor 2002-2005 Ford Explorer
How to Replace Downstream O2 Sensor 2007-17 Ford Expedition
How to Replace Downstream O2 Sensors 2009-2014 Ford F-150
Is my Car a California or Federal Emissions Vehicle
How to Replace Downstream Oxygen Sensor 1997-2003 Ford F-150
How to Replace Downstream O2 Oxygen Sensor 1994-2004 Ford Mustang
How To Replace Passenger Side O2 Sensor 1997-2005 Ford F150
How to Replace DownStream O2 Sensor 1993-1997 Ford Ranger
How to Replace Downstream O2 Oxygen Sensor 2006-07 Ford Explorer V8 4-6L
How to Replace Downstream O2 Sensor 2001-2005 Ford Explorer Sport Trac
How to Replace Upstream 02 Oxygen Sensor 1998-2002 Lincoln Navigator
How to Replace Downstream Oxygen Sensors 2009-2010 Ford F-150 54L V8
How to Replace Downstream O2 Sensor 1998-2011 Ford Ranger 23L L4
How to Replace Downstream O2 Oxygen Sensor 2003-2011 Mercury Grand Marquis
How to Replace Downstream O2 Oxygen Sensor 1998-2002 Lincoln Navigator
How to Replace O2 Oxygen Sensor 1990-2010 Ford F150 Truck
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
Torque Wrench
Socket Driver
O2 Sensor Socket
Copper Anti-Seize
Tools used
Torque Wrench
O2 Sensor Socket
Ratchet
All right, friends, it's gonna be time to get started on our downstream O2 sensor. First, you want to make sure that you have the correct O2 sensor. The downstream is gonna be the one that's located on the rearward aspect of the catalytic converter, and it's gonna have the shorter wire. The upstream O2 sensor is gonna be located on the same pipe, but it's gonna have a much longer wire and a different connector. I'm just going to use our O2 sensor socket here, we'll get it on there and break this free.
The next thing we would wanna do is follow that wire to the connector. There's gonna be a little push tab that you're going to push on, and then you're going to separate the two pieces. There we are. Go ahead and grab that wiring, bring it down to the O2 sensor and then remove your O2 sensor. There it is, friends. Now it's gonna be time to install our brand new O2 sensor. I'm just gonna take the wire go over the driveshaft. We'll go ahead and start this in, bottom it out and then we'll torque it to 46 foo-pounds. Just use a tiny bit of dielectric grease inside the electrical connector, and let's get it connected in, give it a nice click and a nice tug, make sure it's completely secured. And, of course, if it came off the bracket, just make sure you re-secure it with something. Lastly, let's go ahead and put this back inside there, and you should be good to go.
Tools used
Gloves
O2 Sensor Socket
Jack Stands
Wheel Chocks
22mm Wrench
Anti-Seize Grease
Ratchet
Floor Jack
Safety Glasses
Tools used
No Tools Needed
1. Determining Your Emissions Specification
Open your hood
Locate your catalyst sticker
If the sticker says "This vehicle conforms to California regulations," you have a California emissions vehicle
If the sticker says "This vehicle conforms to US EPA regulations," you have a federal emissions vehicle
If the sticker lists both EPA and California regulations, you have a California emissions vehicle
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.
Determining whether or not your vehicle is a California emissions or a federal emissions vehicle is pretty straightforward. To do this, you'll want to locate your catalyst sticker under the hood of your vehicle. It'll either be actually on the bottom side of the hood, most GM vehicles have it on the air box, and other vehicles may have it along your radiator support at the front of the engine bay.
All you need to do is see, "This vehicle conforms to California regulations." That means that this vehicle is a California emissions car. Just because you're not in California or are in California doesn't necessarily mean your vehicle will be one way or the other.
Now, our F150 has it down here on the radiator's support, right at the front of the engine bay and you can see here, "This vehicle conforms to US EPA regulations." This means that this vehicle is a federal emissions.
Now, here we have two things that are a little different. Our catalyst is located on the vehicle's air box and this vehicle conforms to US EPA regulations and California regulations. If it conforms to both federal and California emissions, it's considered a California emissions vehicle.
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
O2 Sensor Socket
Ratchet
Pocket Screwdriver
Tools used
Gloves
Flat Blade Screwdriver
O2 Sensor Socket
22mm Wrench
Safety Glasses
Tools used
22mm Wrench
1. Removing the O2 Sensor
Loosen the bolt on the sensor with a 22mm wrench
Twist out the sensor
Disconnect the wiring harness
Remove the O2 sensor
2. Installing the O2 Sensor
Twist the O2 sensor into place
Tighten the 22mm nut
Connect the wiring harness
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.
Right here on the passenger side of the tuck, on the rear, right behind the catalytic converter, is your rear O2 sensor. It's also known as a downstream O2 sensor, and it's quite easy to take out on this truck. This one actually has a newer exhaust system in it, which is actually making it even easier for us. If yours is old and rusty, it'll take a little bit more force, but it'll still work the same exact way. We're going to start with a 22 millimeter wrench on the O2 sensor itself. We should be able to loosen it up just like that. There is such a thing as an O2 sensor socket, which also makes life a little bit easier. There you go, it's actually out of the pipe that easily.
An O2 sensor socket will make it easier because it fits around the whole socket, or the whole O2 sensor itself, and it allows the wires to go through. So you can use a big breaker bar if you need to instead of a wrench that might slip.
Up at the top of the sensor is a connector, which you need to disconnect to get the sensor out of the truck. Looks like it's going to be a two handed thing. I apologize for kind of blocking the camera there, but you can see this is how the clip works. You push down the tab right here and it releases it from the other connector. Whenever you install an O2 sensor, you never want to plug it in first. You always want to install it first, because when you install it. It's going to spin and if the connector doesn't spin, you're going to bind up all the wires and sometimes it'll actually damage the wire. If you're ever putting an O2 sensor in, make sure you screw it in first. Then once it's all the way screwed in, then you plug it in.
Same 22 millimeter wrench is what we're going to use to tighten it. At that point, you can go up to where you disconnected it. It's the blue connector right on top of the transfer case. Where the transfer case meets the transmission, I should say. At this point, it should snap right into place. Just like that. You'll feel it click.
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
Wire Ties
7/8 Inch Wrench
Wire Cutters
Tools used
Hammer
Rust Penetrant
Jack Stands
Floor Jack
Wire Cutters
7/8 Inch Wrench
1. Removing the Oxygen Sensor
Raise and support the vehicle
Disconnect the oxygen sensor electrical connector
Cut the oxygen sensor wire with wire cutters
Remove the oxygen sensor with a 7/8" wrench
Strike the wrench with a hammer if necessary
Apply rust penetrant to the sensor if necessary
2. Installing the Oxygen Sensor
Remove the shipping protector from the oxygen sensor
Thread the oxygen sensor into the catalytic converter
Tighten the sensor with a 7/8" wrench
Connect the oxygen sensor electrical connector
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, we're going to show you how to replace the downstream oxygen sensor on this 2006 Ford Explorer. It has the 4.6 liter engine. We show you on, I believe the passenger side; driver's side's the same procedure. We hope you like the video. Please click subscribe. Check out 1AAuto.com for all your parts needs for your Explorer or whatever vehicle you might have. Here are the items you'll need for this repair.
Raise and support your vehicle with jack and jack stands. We have ours on a lift. The downstream oxygen sensors are the ones that go right into the catalytic converter. Passenger side is here and driver's side is over here. We're going to show you how to replace the passenger side one.
Follow your oxygen sensor connection up to this blue connector here. There's a tab right here. Press with your thumb and pull to disconnect. To remove your bad O2 sensor, just use a pair of pliers or a pair of wire cutters and cut the wires. That allows you to easily get a 7/8ths wrench right down and on. Many times these are in there kind of tough, so I like to use a hammer just to give it some impact. A few hits will loosen it up. Use some rust penetrant and let it sit. And then I've got it out a little bit and then put rust oil on there, rust penetrant, and now I'm actually going to thread it back in and see if I can work some down in. The old sensor is out.
Here are the old sensor from the vehicle and the new one from 1A Auto. Remove the shipping protector before installation. The connections are exactly the same. The oxygen sensors are exactly the same. The one from 1A Auto is going to be a very good replacement. It's going to fit and function just like your original. New oxygen sensors are available at 1AAuto.com.
Thread in the oxygen sensor. Use a 7/8ths wrench and use the open end to tighten it up. And then just make sure your lead goes up and the tab is down to go into the connector and plug it in and make sure it clicks.
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
O2 Sensor Socket
Ratchet
Tools used
O2 Sensor Socket
Jack Stands
22mm Wrench
Ratchet
Floor Jack
Pocket Screwdriver
Tools used
Gloves
O2 Sensor Socket
Jack Stands
Wheel Chocks
22mm Wrench
Ratchet
Floor Jack
Safety Glasses
Tools used
Sandpaper
Torque Wrench
Gloves
O2 Sensor Socket
Jack Stands
Wheel Chocks
Ratchet
Floor Jack
Cloth Rags
Safety Glasses
Tools used
Gloves
O2 Sensor Socket
Jack Stands
Wheel Chocks
3/8 Inch Drive Ratchet
Floor Jack
Safety Glasses
Tools used
O2 Sensor Socket
Jack Stands
22mm Wrench
Ratchet
Floor Jack
Tools used
22mm Wrench
1. Removing the Driver Side O2 Sensor
Locate the O2 sensor on the driver side of the truck behind the catalytic convertors
Loosen the O2 sensor with a 22mm wrench
Disconnect the wiring harness
Remove the O2 sensor
2. Installing the Driver Side O2 Sensor
Tighten the O2 sensor by hand without twisting the wires
Tighten the O2 sensor with a 22mm wrench
Connect the wiring harness
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 a 100% satisfaction guarantee. So visit us at 1AAuto.com, your trusted source for quality auto parts.
Right here, on the driver's side of the truck right behind the catalytic converters you'll find an O2 sensor. This is the rear O2 sensor, also known as the downstream sensor, and it's pretty easy to disconnect on this truck, especially in this case because this truck actually has a brand-new catalytic converter pipe and it has relatively new O2 sensors. So we're going to show you how to replace them.
We're going to use a 22 millimeter wrench. You can come up from the front and get the wrench on their pretty easily, and then it's just a matter of pushing up to loosen the O2 sensor. Then, if you follow the wire up to the top of the transfer case, you can see it plugs in right here. And if you pull on, if you push the little tab down, right here, and then pull on the connector, it should slide right out. At that point, you can come right back around and spin your O2 sensor right out of the exhaust system, just like that. There we go.
When installing the O2 sensor, you always want to put the O2 sensor in first and tighten it up rather than plugging it in first, and that way it makes it so your wires don't get all bound up. So right now, you can spin it into the hole and make sure that the wires aren't getting all twisted up at the same time. Because if you twist the wires up, sometimes they'll actually get damaged and we don't want to do that. So, we'll use the same 22 millimeter wrench to tighten up the O2 sensor from the front just like when we loosened it.
All right. It's nice and tight now. And at this point we can feed the wire up over the transfer case and we can play it right into the wire harness, just like that.
Thanks for watching. Visit us at 1AAuto.com for quality auto parts, fast and free shipping and the best customer service in the industry.
250-24001
In Stock
Product Reviews
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Explorer O2 sensor
Jack
August 12, 2019
Great quality perfect match. 1A auto video great
Customer Q&A
Is this for bank 1 sensor 2 on a 96 ranger 2.3-4 cylinder?March 5, 2022
Jacob D
10
Yes, this part will fit both upstream and downstream locations on your vehicle.
March 7, 2022
Andra M
Is this for bank 2 sensor 1? Need it for my 96 crown vic.February 6, 2024
Elijah T
10
I purchased this sensor for my 1997 F-250HD with a 7.5l engine. I installed this sensor on the passenger side of the exhaust pipe close to the catalytic converter. I hope this helps.
February 7, 2024
Guillermo D
10
Yes, this part will fit your vehicle in both the upstream and downstream positions.
February 7, 2024
Meghan R
10
This it For Toyota Highlander
February 8, 2024
Carlos P
10
Thx
February 19, 2024
Chrisnord L
Is walker oxygen sensor 250-24001 a narrowband sensor or is it wideband?September 13, 2024
Samuel B
10
This sensor will have the same specifications as your original equipment. Please confirm fitment with our fitment chart before placing your order.
September 16, 2024
Nick R
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