Oxygen sensors

[Hauser717]

Check engine light reared it's ugly head today. When I got home from work I found the following codes: P0174, P2195, and P2197. From what I've found in the forums is that it is most likely the oxygen sensors as I'm pretty sure they're the originals from 2004. The Merc has 144,000 miles and I've never changed 'em in the 104,000 miles that I've enjoyed her.

So the question I have is whether or not I can do this at home. And if so, where are the sensors located? (A guide would be awesome if one exists) I am also presuming that the Motorcraft replacement parts are the best ones to get?

Thanks in advance,
Haus

[massacre]

There are several types but if you want to do this yourself you will prob need one of these:
http://www.google.com/search?q=oxygen+sensor+socket&client=safari&hl=en&source=lnms&tbm=isch&sa=X&ei=nGvLUruFD9LjsASQ1YHYDQ&ved=0CAkQ_AUoAA&biw=1024&bih=672

[ctrlraven]

Found these with the code P2195. You may want to check your PCV hose connection.

http://www.youtube.com/watch?v=_T0Td7HiEJk
_T0Td7HiEJk

If you have to replace the O2 sensors, only go with Motorcraft. Front ones are Upstream and rear ones are Downstream. If you have a tune for the car, most likely the rear sensor are turned off so you only need to worry about the Front/Upstream ones. I bought mine from Rockauto.com and replaced them myself. Not really hard if you have the right tools, space to work and time.

[tbone]

The front sensors are kind of a pain to get off, especially the drivers side, but can be done with an open ended wrench, one tiny turn at a time. The rears could be swapped by a toddler. Breaking them loose can be a challenge though.

[fastblackmerc]

The front sensors are kind of a pain to get off, especially the drivers side, but can be done with an open ended wrench, one tiny turn at a time. The rears could be swapped by a toddler. Breaking them loose can be a challenge though.

Spray some PBlaster on them and get the exhaust hot, they will come out easily. Be careful not to burn yourself.

[Marauderjack]

The one closest to the engine on the driver's side was A LOT of fun on mine.....finally got it out with a "Crow's Foot" hickey!!:argue::mad2:

[babbage]

The fronts are the ones you want to change. 10 years/100K+ they are toast.
Use either OEM or (NGK/NTK)

[vegasmarauder]

Google "Ford O2 sensor Wrench". This special tool makes it a lot easier to remove the uppers. Some of the parts stores can loan them out. Much easier than open end wrenches.

They can be bought for about $20 on Ebay, but not worth it for just one change.

[VMARAUDER]

Spray some PBlaster on them and get the exhaust hot, they will come out easily. Be careful not to burn yourself.
What he said or spray some SeaFoam Deep Creep and heat it with a torch and comes out easy too.