[joseph_gray_02]

Hello, I am new to the Cougar forums. I know the car has two oxygen sensor's and my check engine light has came on and i get it read at autozone and they told me it was an o2 sensor. i hear an awful noise coming from the air box when the car is turned on before any acceleration occurs...any idea what this sensor looks like or where it is how difficult is it to change? thanks.

 

[dfwcatsclub]

Joseph,

The O2 sensor is *always* located in the exhaust system. It screws in to the exhaust pipe somewhere right after the engine underneath the car. It's about 3" long and has 3 or 4 wires hanging out of it which go to a wiring harness.

Good luck.

 

[cougarshaman]

The airbox noise sounds strange.
Occasionally the airbox can buildup water and it makes the computer do weird things as it processes airflow and exhaust.
Check out the airbox.
And, o2 sensors should be changed regularly anyway. About every other oil change.

 

[TheRktmn]

And, o2 sensors should be changed regularly anyway. About every other oil change.

Really? I have a '99 and an '01 and I have never heard that. Is it in the owners/maintence manuals? I can't find it.

 

[cougarshaman]

My info on O2 sensors comes from Bosch and Bumper to Bumper auto parts propaganda. Also from an article I read in Hot Rod or Car Craft a couple of years ago.
Apparently the sensor gets clogged, but will work to some degree (or variety of degrees) when it gets some age on it. Until it goes kaput that is.
But, it's made to be a throwaway part like a sparkplug.
According to Bosch and Bumper to Bumper, to keep a car running to it's utmost emissions and mixture capabilities, the sensors should be changed every other oil change.
According to HRM/CC mags, if you have a computer controlled car that is bein hot-rodded or run hard, then changing the sensors often makes sense.
In higher end cars like Ferarri (Modena) and Porsche (911,935, etc) they have it on the regular dealer maintenance schedule.
FoMoCo does it on their flex fuel cars.

But, since the sensor is the eyes and nose of the computer for enrichment/leaning purposes, it makes sense.
I change the sensors in my Girlfriend's V6 LeBaron about every other and it runs like a top.
A mopar top, that is.:-D

 

[radcat68]

What year & make vehicle, size engine do you know the number to the codes that was in it.

 

[CrazyCat]

there is no need to change the o2 sensors unless you have a problem, or have 75-100k on the car. Of course Bosch tells you to replace them frequently. They want your $.
I doubt it is every other oil change though.

 

[TheRktmn]

It seems to me that the spark plugs are more apt to burn dirty and cause a drop in MPG before the O2 sensor gets clogged. I have never changed an O2 sensor that the computer didn't report as faulty. I called my ML dealer and asked them about this - they said they had never heard of such a thing and if it ain't broke, don't fix it.
Thanks for the info, but I will go by the onboard computer and my MPG. I have a problem with replacement parts manufacturers recommending that I replace things just because.

 

[cougarshaman]

Yeah, I don't blame you there.
Now that I think of it, that's probably more the case. Selling parts.

However, on a hotrod, it seems to make a difference.
I picked up a tenth on a 92 stang at the drags just changing the o2 sensor last fall.
*shrug*