Easier way to change rear, upstream O2 sensor

[dylanborns]

I just changed the rear bank, downstream O2 sensor on my '01 Escape V6 due to a check engine light and the code saying it was bad. My mechanic recommended I do the other 3 even though I wasn't getting any error codes or having any issues. He said that they get clogged up and dirty and that will cause lower efficiency and bad gas mileage, and that if one has gone bad the others may not be far behind.
So, I decided to do the other rear bank, upstream sensor. I googled it and also looked through my manual, and I've mostly found that removing the passenger tire and alternator is the easiest way to get to it, or jacking up the car and doing it from underneath. I just happened to be replacing the front 3 ignition coils today, and after removing the engine cover, I took a look down the back and saw the sensor in arms reach. Here are the steps I took to replace it.

Remove the engine cover by taking the 3, 8mm nuts off. If you look down the back of the motor, right in the middle you'll see this:

The green connection is what you are trying to get to.
Look farther down and you'll see this:

The blue arrow is pointing to the electrical connection, and the red is the actual sensor in the manifold. You'll need a flashlight to see the sensor. I sprayed some PB on it and let it sit a few minutes, then disconnected the electrical connection. I slid an O2 sensor socket down there and was able to get it on the nut on the sensor. Make sure and put the open side of the O2 socket down, so that if its not on the nut just right, it doesn't fall off and end up down under the motor somewhere. Put it on like this as if this sensor was still in the manifold:

I dropped the socket a couple times until I put it on like that and it was pretty tough to find up under the motor. Remove the old sensor.
To get the new one in, fish it down in there and plug the electrical connection in first. It will start winding up when your scr**ing the sensor in, but it helps keep it out of the way. Once you get the new sensor in and seated, unplug the connection, unwind it, and use the socket to tighten the nut down. Then reconnect the electrical connection. Replace the engine cover and do the steps to reset the PCM. Your done!
By the way, this is what the upper sensor looked like:

Its pretty "carboned up", and even though it wasn't throwing any codes, looks like it was needing to be replaced.
Hopefully this helps anyone that is needing to do the sensors.