O2 Sensor locations?

[Michael Nelson]

Hello all, I'm new (obviously).

I just bought a 2000 Crown Victoria Police Interceptor with 87k miles. Naturally it has some issues, most of which I've dealt with.

So the "Check Engine" light is on, the Ford service say I should replace the O2 Sensor (which one?).

They want to charge a huge amount, and I can't afford that right now.

So I was wondering where are the O2 Sensors located? Are they as easy to install as the Air Flow sensor? If they are easy to do myself I'll be saving like $400.

TIA for any help.

[Johnny Mullet]

You gotta find out which )2 sensor is bad, and the code from the scanner would tell us. There are 4 02 sensors on that! It may not even be a sensor. You could have a PCV system leak or an intake leak.

Get a free scan and post the code here.

[MT-2500]

Originally Posted by Michael Nelson

Hello all, I'm new (obviously).

I just bought a 2000 Crown Victoria Police Interceptor with 87k miles. Naturally it has some issues, most of which I've dealt with.

So the "Check Engine" light is on, the Ford service say I should replace the O2 Sensor (which one?).

They want to charge a huge amount, and I can't afford that right now.

So I was wondering where are the O2 Sensors located? Are they as easy to install as the Air Flow sensor? If they are easy to do myself I'll be saving like $400.

TIA for any help.

Welcome on your first post on AF.

As just said we need that code no.
A check engine light or a 02 sensor code does not say replace the sensor.
It says check it out.
Many things can give you a 02 code.
What is the mileage and how is the tune up end?
What engine and what is the code no?
MT

[Michael Nelson]

Thanks for the replies, the Ford Dealer service said I need an O2 Sensor. I only know of 2 for my car. I took it to AutoZone for a free scan and it came up something about the air and yes I forgot the code. They said it was generic and didn't know specifically what it meant.

If I can figure out where the sensors are located and if they are easy to replace I'm going to do that anyway. The car runs pretty good.

You asked for mileage, it has about 87k now.

[MT-2500]

Originally Posted by Michael Nelson

Thanks for the replies, the Ford Dealer service said I need an O2 Sensor. I only know of 2 for my car. I took it to AutoZone for a free scan and it came up something about the air and yes I forgot the code. They said it was generic and didn't know specifically what it meant.

If I can figure out where the sensors are located and if they are easy to replace I'm going to do that anyway. The car runs pretty good.

You asked for mileage, it has about 87k now.

Close to tune up time.
But if you want to throw away 500-750 $ in about 4 or 5 02 sensors go ahead.
It is your money.
Or post back code number and a little more info and someone will help you.

[Michael Nelson]

Originally Posted by MT-2500

Close to tune up time.
But if you want to throw away 500-750 $ in about 4 or 5 02 sensors go ahead.
It is your money.
Or post back code number and a little more info and someone will help you.

I'll go get it scanned again, but like I said it was an unspecific code.

Also just how many sensors does my car have? Because to order replacements anywhere it shows only 2.

I'm really asking where they are located and how difficult to change them. I know that these sensors should generally be changed anyway after about 60k miles.

[BMW320i]

You need a special socket. Most stores carry them. It is a deep socket with a part of the side cut out for the wire to go. You need this if there is a clearance issue. You can also use a wrench if there is enough room. There are first always located on the exhaust pipe between the header and the rear muffler. Just get under it and feel around. You will see a wire sticking out and a small thumb sized metal thing attached to the wire and screwed into the exhaust. There is one before the CAT and one after the CAT. If you have true dual exhaust there will be four, two for each side. If you have sincle exhaust and one CAT then just 2. I have done two different cars O2 sensors. They are about $100 each. I always replace all the O2 sensors together.

[MT-2500]

Originally Posted by Michael Nelson

I'll go get it scanned again, but like I said it was an unspecific code.

Also just how many sensors does my car have? Because to order replacements anywhere it shows only 2.

I'm really asking where they are located and how difficult to change them. I know that these sensors should generally be changed anyway after about 60k miles.

The parts book may only show two different types/kinds BUT.
You may have up to 4-6 sensors on it.
No need to change them unless they are bad.
And sometimes when you get to fooling with them you may stir up more trouble.


They are located from the exhaust manifiold all the way back to behind the cat.
Look around under there.
Some are easy to change and some are a bitch to change.
Do not replace them unless they are bad because Sometimes they outlast the car.
And a lot of times a 02 sensor code is caused by something else.
How is the tune up end on it?
A poor runing car in need of tune up stirs up a lot of 02 sensor codes.
Get the code and post back for help with it.
MT

[Michael Nelson]

Originally Posted by BMW320i

You need a special socket. Most stores carry them. It is a deep socket with a part of the side cut out for the wire to go. You need this if there is a clearance issue. You can also use a wrench if there is enough room. There are first always located on the exhaust pipe between the header and the rear muffler. Just get under it and feel around. You will see a wire sticking out and a small thumb sized metal thing attached to the wire and screwed into the exhaust. There is one before the CAT and one after the CAT. If you have true dual exhaust there will be four, two for each side. If you have sincle exhaust and one CAT then just 2. I have done two different cars O2 sensors. They are about $100 each. I always replace all the O2 sensors together.

Okay I see what you mean, with dual exhaust it would show that there are two but each one is doubled since 2 pipes. Well once I get the car up I'll look underneath thanks!

Depending on the wiring harness they will cost me about $42.99 each, so if I do all of them 171ish. Plus the tool whatever that costs.


The thing is, the car runs really well but that light is on. Yeah I'll get the code again though.

Hey, you know the flap on the gas filler that opens when you put in the nozzle? Well mine is stuck open like it's bent, maybe that could be the cause for the light? You know how they say don't fill your gas while the car is running or the Check light will come on? That's what made me think of it.


Thanks much!

[BMW320i]

I have had several O2 snesors fail in my cars over the years. I have found that though it is always good to replace a part. O2 sensors are not hard to get by without. Thjey just fine tune the fuel ratio for optimal emissions. I have not had a car run bad with a O2 sensor out. I even installed 3 new ones on my Del Sol and the code never left. $40 aint bad for a O2 sensor.

[Michael Nelson]

Originally Posted by BMW320i

I have had several O2 snesors fail in my cars over the years. I have found that though it is always good to replace a part. O2 sensors are not hard to get by without. Thjey just fine tune the fuel ratio for optimal emissions. I have not had a car run bad with a O2 sensor out. I even installed 3 new ones on my Del Sol and the code never left. $40 aint bad for a O2 sensor.

Yeah it's not a bad price, plus it would be great if I could get the service dealer to pinpoint which one to fix (if I need to do just one).

Although I was thinking the light could be due to the gas filler hole flap like I said above. I wonder what that would cost to fix...

[MT-2500]

Originally Posted by Michael Nelson

Okay I see what you mean, with dual exhaust it would show that there are two but each one is doubled since 2 pipes. Well once I get the car up I'll look underneath thanks!

Depending on the wiring harness they will cost me about $42.99 each, so if I do all of them 171ish. Plus the tool whatever that costs.


The thing is, the car runs really well but that light is on. Yeah I'll get the code again though.

Hey, you know the flap on the gas filler that opens when you put in the nozzle? Well mine is stuck open like it's bent, maybe that could be the cause for the light? You know how they say don't fill your gas while the car is running or the Check light will come on? That's what made me think of it.


Thanks much!

Newer systems up to 3 sensors on the main side.
If your heart is all set on throwing parts at it replacing them with them cheap fit all sensors .
Go ahead and mess it up it is your car. Your money.
A good OEM sensor will run you 100-135$ . You do not get much for 42.95.
Good luck MT

[BMW320i]

The flap is to keep large foriegn objects out of your tank. The cap can bring up a code if the cap fails. Worth a try buying another cap. You will have to have someone clear the code and see if it comes back. Most O2 sensor codes have a location. Don't pay the dealer to get your code. Go to a parts store and have them pull it for free. Sometimes they won't clear it for you though. Just inform them you are buying their cap and want the code cleared to see if it was that or if you need to buy more parts. ETC. If you are planning on buying only 1996 and newer cars it is worth it to buy a $100 code reader. I got one and love the hell out of it. DO all my friends cars too. Just get a OBD II code reader. Any generic one will do and they you can search the codes on the net.

[BMW320i]

He is right if you do buy them buy the specific for your car not the ones you have to wire in. Besides it is a pain in the butt to do that anyways. My Honda I mentioned had to have a cheap ones at $100 each since honda wanted like $300 each. I never got rid of the code as I told you above. At least get a good brand OEM replacement if the dealer cost is too high.

[Michael Nelson]

The only sensors I saw were from $42.99 for OE to $60.00. Anyway like I said before I do anything at all I'm going to get it read again, and write down the code to post it.

I'll try to get them to clear it and use that reasoning only I'll buy some gas "treatment" and say that's what I'm using to fix it.