Well it was a nice 45* out today and I have been getting really bad fuel milage latly so I decided it was time to replace my O2 sensor on my 7. And for only $16.99 I think it was worth it. Ok here we go:

Tools Required:
1/2in drive breaker bar (or a impact wrenc if you have air tools)
Long 1/2in drive extension
1/2in to 3/8in adapter
O2 Sensor Socket
Crimper (or a screwdriver and a hammer... thats what I used)
Knife
Lighter


1. Locate your O2 sensor plug and unplug it. It should be green and it's pluged into a milky white connector. It is behind the intake manifold, close to the secondary fuel rail. Note that it has a tab on the top AND bottem of the plug. I found this out the hard way



2. Get your breaker bar - extension - adapter - o2 socket out and put that sucker on the O2 sensor. You may have to move the cruse control thingy out of the way if you have one. Remove the O2 sensor from the car



3a. Look at your old O2... looks like hell dosn't it? I know mine did. Cut the wire off the old O2 if your using a universial O2. If your using a OEM replacement your almost done.
Old on left, new on right


3b. (This step only for a universial O2) Strip the wire leading to the plug. Put the heat shrink that the new O2 came with down the wire for later use. Insert the striped wire in the new metal connector and crimp. Slide the heat shrink over the connection and use a lighter to shrink it.

4. Install the new O2 sensor. I just tightened it RFT (really ******* tight ) then plug in the connector.



5. Your done! Take it out for a test drive. Watch your gas milage over the next tank of gas or so and see if your milage is any better.

BTW this cost me a total of $28.60 becasue I couldn't find my old O2 sensor socket... oh well

 

I'll rate it a 5. Might want to note that having an ABS pump turns this into a PITA.

 

oh yeah forgot about that, i'll add it in a sec
edit: i guess you cant edit after someone posts, oh well

 

don't forget the anti seieze

 

it already comes with it on the Bosch sensors

 

It's also a pain if your car's a turbo and a aftermarket DP...def. on the SSAUTOCHROME one, the little white part at the top of the sensor was hitting some AC tubing, I had to trim off the white part.

 

That was a good write-up and good pics, but if you're getting "really bad fuel mileage" it won't be because of your O2 sensor. It's effect on fuel consumption is very overrated. In my experience the difference in fuel consumption between a brand new O2 sensor and no sensor at all is less than 5%.

 

meh oh well, it needed to be done eventually, and like i said, for $17 i might as well do it

 

Yeah, I agree... in fact I have seen minor gas mileage drops; more than a couple of times with a new O2 sensor.

 

Absolutely, any reduction in fuel consumption (not to mention emissions) is a good thing.