I thought I would post this here as I had to replace my downstream sensor (the one after the catalytic converter) because I had a DTC code for it. I used a Bosch Exact Fit (per the Bosch website) for my 2003 Ranger 3.0 Automatic for the one after the CAT (Downstream). While I had the inner fender wells out I realized I can access the sensors very easily and after 244K miles on the original ones I decided to change those also. These are the 2 before the CAT (Upstream).

Here are the part numbers:
O2 Sensor Downstream - Bosch part number 15716, you only need one.
O2 Sensors Upstream - Bosch part number 15664, you will need 2.
One for each side of the engine, they are located right after the exhaust manifold (there is one on the driver's side and one on the passenger side (bank 1 and bank 2).
I hope this helps.

 

Good stuff thanks

 

HEY, will those same sensors #'s work on 1998 3.0 Ranger ?

~tb

 

They might. Here is what I did to be sure of correct fitment: I googled Bosch and on their website I was able to enter my truck year and engine and it gave me all of the products they make for it. The 02 sensors are listed down further in the page:

Here is a link:

https://www.boschautoparts.com/en/

Let us know if this was helpful, happy searching for the right part.

 

...THX for the web site....went there , checked it out..... they show 5 different ones for my vehicle. 1 seems to be the one closest to the Cat. the others are seemingly the same but all have diff. part #'s ????? Sorry i'm no mechanic, i'm confused ??? If you have any further Wisdom, please advise, I will continue to research .......

Thanks again , ~tb

 

T0mmyB,

No worries I can try and help. Are you replacing all 3? I mean there are 2 one on each side before the Catalytic Converter and 1 after the converter. The reference of their perspective position is based on the Catalytic Converter. For example: Downstream meaning after the catalytic Converter and our trucks have only one. Give me the year and engine again, is it Flex Fuel, and let me look at it and give some recommendations. Glad to help out!

 

YES, was gonna change all 3, .....2 (bank 1 & 2) AND the Cat one. It's a 3.0 - 1998 6 cyl. gas.

 

1986 to 2011 Rangers all used the same type of O2 sensor, heated/narrow band O2

Part number difference relates to the Length of the attached wires
O2s come with a 6" to 3ft wire harness attached
The Length of the O2's harness in no way effects the O2 performance, its just to reach the Vehicles plug in for that O2 sensor

There is no "rear" or Cat O2 sensor, its the same sensor as the one, or ones, closer to the engine, so you can't really go wrong unless the wiring harness is too short

 

So your sayin' other than the wire length, they're all the same ?

 

RonD has some good information!

Here is what I get for your truck based on the Bosch Website:

you need 2 Bosch Sensors for the left and right side: Part Number:15717

And one Bosch Sensor located after the Catalytic Converter:

Part Number:15719

When I purchased mine they were the exact wire lenth so I didn't have to worry about tucking the extra lenght of wire so it does not get damaged, it was exactly like the originals I removed length wise. Shop around for the best price now that you have the part number and let us know how it turns out. Remember if you remove the inner fender well you have much easier access to the sensors.

Hope this Helps

 

Yes, 1986 to 2011 all Rangers used the same O2 sensors, they are heated narrow band O2 sensors, at any location in the exhaust system

Later years have switched to heated Wideband O2 sensors, these require a different computer software to use

O2 sensors use a chemical reaction to detect Oxygen in the exhaust, and they simply run out of chemicals, 100k miles or 12 years is when you should change them
The engine won't stop working because O2s are too old, lol, but you will start to see a drop in MPG the older they get, so $$$ out of your pocket at the gas pump

 

OxygenSensor locations on your 2003 are likely similar to my 2001, pictured below.
Click here for more info.

 

Hey HT08,
I finally got those sensors & an opportunity to replace all 3. YOUR info. was Great So i'm back for more !! :-)
I got the one near the rear exhaust put in, then the passenger side one in, when i got to the one on drivers side WOW what a pain !!...... someone had already been there and kinda rounded the edges of the 22mm sensor edges. Can you advise me a good way to get to this thing and get it out ? i bought a "sensor box end" to get it out, was great on other side but not so much on this side. Thought i'd ask you for your recommendations ?? My buddy thinks we may need to pull all the exhaust to get to easier....man thats crazy !!!!

Thanks for ANY ideas HT08 !!!

 

Rather than struggle with rusted exhaust parts, which can take you hours and hours, even a day or two, lol

I go to a local exhaust shop, an independent shop, not a chain, and ask them to remove a part, like rusted bolts or in this case O2 sensor, and offer cash
They have ALL the tools for rusted exhaust parts and torches and knowledge, they do it daily, lol

If it takes them longer than 15min to remove the old one and put in the new one it would surprise me

In my younger days I would fight with exhaust stuff, buy more tools, lol, need ANOTHER right tool for the job

Your O2 is obviously rusted in place since others have tried to change it, so take it to a "pro" that does this for a living

 

Great advice right there from RonD, especially when it's rounded off. The only other suggestion is removing the inner fender well for accessibility, using heat as in (a torch to apply high heat to it) and a large vise-grip. Good Luck!

 

Thanks for this picture. I had searched everywhere and could not find this. I have a 2001 3.0 (regular gas) and just replaced all three of these. This confirms that the job was done right, and the sensors were the right ones. Now have no more codes, and runs like a top! Have 250,000 miles on it, and am now looking forward to much better fuel economy.

 

That's Great! Thanks for the update :)