1997 Ford Taurus O2 Sensors

EMTMAN07

MEMBER
1997 FORD TAURUS
6 CYL
FWD
AUTOMATIC
197,000 MILES

Ok, I went to change the o2 sensors on my taurus. I went to autozone to buy the new o2 sensors. They told me there was 3 on the car. 2 up front and 1 behind th converter. While I was changing the (3) sensors, the one in the middle that I was changing, I happened to look over and up a little bit and noticed appeared to be a 4th o2 sensor. So now im very confuse which 3 are the o2 sensors, and what the other sensoe looking device is. How do I know which ones to change? What is the 4th device. Is there pictures anywhere on the net or a manual that would show me which ones are which? Im changing these because my exhaust system is coming out in puffs rather than just a stright flow of exhaust. I changed the mass air flow sensor, and that did nothing. What esle could be the problem?

10 Replies

IMPALASS

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3,112 POSTS

Hello -

To better assist you please tell me if your model is a G, GL, LX, or SHO. Also your engine size in liter and the 8th digit of your VIN.

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Friday, March 20th, 2009 AT 7:15 PM

EMTMAN07

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Ok its a model gl, 3.0 liter.
Heres the whole vin number.
1FALP52U5VA224295.

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Wednesday, March 25th, 2009 AT 4:53 PM

IMPALASS

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Hello -

I show 4 O2 Sensors. You should have 1 on each exhaust manifold and 1 after each catalytic converter. I have attached a pic of the wiring diagram.

Why did you decide to change them. . ..did you have a DTC code to do so?

What color is the smoke?

If you haven't please go to Auto Zone (AZ) or O'Reilly's (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don't get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

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Wednesday, March 25th, 2009 AT 8:56 PM

EMTMAN07

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I changed them because a few months back my service engine soon light came on and was just staying on. Then I noticed the car giving hesitation and making backfire popping noises from under the hood. The service engine soon light then started blinking and its been blinking ever since. So I took it to autozone and they put it on their tester. Im not sure what the codes were that it read but the guy at autozone said that it said, cylinder 1 misfire, cylinder 2 misfire, and then the mass air flow sensor and the o2 sensors were bad. So that day I changed the spark plugs, spark plug wires and mass air flow. I notcied when I changed the plugs and wires, that the wires on 1, 2, & 3 plugs just fell off like burned dried up rubber when I went to pull them off. Anyways, I chaged those things to see if it helped. Well the next day it was doing the same thing. I finally went to get the o2 sensors, and thats when the guy at autozone told me there was only 3 o2 sensors on the car and the 2 in the back were different from the one in the front and he gave me the wrong o2 sensors on top of that. I finally went and got the right ones today and changed the o2 sensors today, all 4 of them. And its still kinda hesitant when I give it gas and the exhaust is still puufing out, not a normal straight flow. Its got some liquid coming out slowly with the smoke, but I wasnt sure if thats just water from the heat of the exhaust or what. You cant really see the smoke unless you get right up on it and stare at it. But the smoke is a very light blue, almost white smoke, but it appears to the eye as almost like when you open a freezer door and the cold air is coming out. Its not solid smoke. And the smell of it is like a strong rich smell! The service engine light is still on, but its not blinking anymore. Should I take it back to autozone and have them test it again and get the exact codes its giving them? Thank you soo much for your help so far, I will definately owe you guys a bigger donation when im done!

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Wednesday, March 25th, 2009 AT 10:07 PM

IMPALASS

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Hello -

Thanks for the info - you have been busy.

Well, you changed the plugs and wires....... Do you remember what the plugs looked like?

First - just some advice... Any time they pull the codes, get the code number and what their tester says it is. We compare that to what the manuals say the code is. Sometimes the codes are generic and may not be the exact one..... But that will help.

For now, take a spray bottle of water and mist/spray it all over the plug wires while it is running and tell me what you have.

Check your coolant to see if there is any signs of engine oil in it.

Check your oil to see if there is any sign that there is coolant in it.

My concern now is the smoke. With the miles you have on it and possible white smoke, that may be a blown head gasket.

For now, do the above tests and yes, please go to AZ and pull the codes again and let me know the code number too besides what they say the code is.

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Wednesday, March 25th, 2009 AT 10:26 PM

EMTMAN07

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Ok, I took the car back to autozone, and I watched the girl plug it in and read the codes. It didnt pop up any codes, so I dont know what she did or was usin, but instead it actually read what it was testing. And the screen said misfire on cylinders 1, 2, 3 and oxygen sensor 1 and oxygen sensor 2. When I oped the radiator cap it did have an odor of oil in it and the inside of the resevoir is stained brown. I do know that years back, my mom used to drive the car, and she had the car looked at and they said that there was water getting into the oil system and they did replace the head gasket. But like I said, that was years ago. I did do the thing where you said to spray a mist over the plug wires, but im not sure exactly what I was supposed to see or looking for.

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Friday, March 27th, 2009 AT 10:43 AM

IMPALASS

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Hello �

Thanks for getting back with me.

Sorry for the delay in getting back with you.......I encountered some technical difficulties.......

Well, not knowing what they did years ago, that is did they surface the heads etc or if the radiator was flushed..... Do you have another blown head gasket.

Have you checked your oil to see if there is coolant in it?

With the engine running at temp... Is there bubbling in your coolant overflow tank?

Is there white smoke coming out your tail pipe?

The mist over the plug wires is to check for sparks that are jumping from the plugs or plug wires to metal objects like the exhaust manifold etc. Sometimes the plug wires are not as thick and insulated as they should be. So as the car is running a spark may jump from the plug wire to say, the exhaust manifold. Now you have a rough idle, maybe it will start to read a misfire since that plug is not firing. The water attacks the spark and the engine will run rough for a second.

Does the car run hot or have you let it overheat in the past?

You may have to flush your cooling system and refill and see if it turns brown with oil again.

You can also purchase head gasket leak detector kits that will assist in checking for head gasket leaks.

The water of course going through the exhaust would give you a bad reading on the O2 sensors...

You stated a backfire earlier.....A backfire from the engine bay can be low fuel pressure or the ignition system. Since you changed the plugs, wires etc it may be fuel. Can you check your fuel pressure?

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Friday, March 27th, 2009 AT 10:24 PM

EMTMAN07

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Its ok about the delay!

Yes, I checked the oil, I did a complete oil change the same day last week when I changed the o2 sensors, and the oil looked normal for changing old oil. It was the normal worn out black color of used oil. No signs of water or a creamy looking color or texture to it.

Yes there is white smoke coming out of the tail pipe! And it has a rich smell to it. Not sure if thats burning oil or gas im smelling!
I did do the mist over the plugs, but I didnt see any sparks and hear anything or notice any loss of power or rough idle when I did that!

The car hasnt ever overheated as far as I can remember or that I know of. At least not in the past 5 years since ive been driving it.

I will go and purchase the gasket leak detector kit to try it out. I will also check the fuel pressure. I did change the fuel filter just a few months ago. Should I try changing it again?

Could a bad exhaust system with old catalytic converters or a worn out muffler be causing exhaust back up or something in the engine?

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Sunday, March 29th, 2009 AT 11:31 AM

IMPALASS

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Hello -

Thanks for the info

Well, sounds like you know what to look for in the oil..... So it may be the oil is moving from the cylinders to the coolant and not the other way around.

White smoke....... That sure sounds like a blown head gasket.

If it is running a little rich it may be due to the water and things not reading right. Usually if it runs rich you may have problems with Manifold Air Temperature sensor, engine coolant sensor, or O2 sensors.

But again, if you have a head gasket leaking..... That may be the cause.

Good job on the spraying the water..... The slight roughness or hesitation etc may be the water burning in the cylinders... Which is the white smoke..... So there is no spark jump.

Well, and it may not have overheated. You have 197000 on the car. To me that would be perfectly normal to have the gasket go, the heads warp a little.

No need to change the fuel filter again right now..... Lets first narrow down the possible head gasket leak.

With that many miles your cats may be going..... To be sure, first I would get the head gasket leak checked. If those need to be redone, then get that accomplished then take it to a muffler shop and they can check out the cats and muffler. Right now if you do have a blown gasket that may be giving your cats a hard time too.....

Keep me posted

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Sunday, March 29th, 2009 AT 5:22 PM

IMPALASS

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Hello -

Also, it looks like you may have some recalls on your vehicle. The dealer may fix these for free. Please contact the dealer service department, give them the VIN number of your car and have them check on these to see if they apply to you.

It is a 1997 so they may have been fixed already but it doesn't hurt to check.