Looks like it takes a 22mm wrench for the sensor. Do i use a regular open end wrench. Is shorter or longer better? Chilton book says to run the engine a couple minutes to expand the metal and loosen the fit. Any other advise?

 

97 legacy 2.2

Edited March 20, 201016 yr by JohnKos
added model

You got it! 22mm, longer handle is better 'cause you're gonna need some leverage to crack it free. Penetrating oil then a bit of warm up really helps.

 

Good luck.

closed end wrench if you have it (7/8 inch will work), slip the wire connector through the wrench first. this will help avoid 'rounding it off'. not a big deal if you are replacing it, but if you can get it out without a headache that is all ways easier.

You can buy this specially made O2 sensor socket at any parts store.About 7 bucks. Or,just use a wrench.

 

Boy, wasn't that just the biggest PITA thing to change. Getting it out was cake compared to try to get the new sensor threaded into place. No room, large fingers. Finally after 10 min it caught and turned right in. A quick tightening, rout the wire and connect... done. Don't feel like doing that again any time soon. Thanks for the advice.

Congrats. Just be thankful--getting the old one loose is usually the PITA part!

Unhooked my battery over night to reset the CEL. How much driving before i know the O2 replacement works? In other words how long for the CEL to go back on if it wasn't the problem?

Would any of you consider using an impact wrench for this job?

CEL would come back on next time you go closed loop (full operating temp) and tell you the O2 sensor is bad. That said; I've had bad O2 sensors that didn't throw codes... just bad fuel milage. Keep an eye on the CEL and track your MPG accurately.

 

 

 

There's really no need for any air tools on this job. The threads are so coarse that once it's broke free you can do the rest by hand. It is tricky to line up the threads when reinstalling which usually makes it easy to crossthread with air tools. I like my air tools but wouldn't use them on an O2 sensor replacement for reasons metnioned above plus I dunno what that impacting would do to the sensor itself.

Edited March 22, 201016 yr by MorganM

You'd have to cut away a bunch of the frame to make room for an impact gun.

I barely had room for my fingers

I just did a O2 change on my former turbo leg. Fun to remove the chimney to get to it. At least i had only put back in 1 of the 6 chimney 10mm bolts holding it on from way back. It was a breeze.

Fun to remove the chimney to get to it.

 

You have a chimney? How many miles to a cord of wood do you get?