2000-2004 Avalon O2 Sensor Replacement Guide

[RexG]

So I've read a lot of posts on how to change O2 sensor and here's my review after just replacing mine.

My check engine light came on again so I took it to my local Advanced Auto Parts Store to get free code check.

I figured it was just the same old tighten gas cap code I seem to get 1 to 2 times/year and I would just need to reset by disconnecting the battery.

Well it ended up saying I needed to replace bank 1 O2 sensor (which after reading some other posts is the one nearest to firewall) the harder one to get to.

I was going to just get the O2 sensor at Advanced but after doing some research I found a better deal at RockAuto where I was able to get a Denzo O2 for $101.62 and that included shipping.

When I first found it I thought it would be really hard to get out but follow my method and it should be pretty easy.

First thing I did was reach down and sprayed it down with PB Blaster several days before I actually received the part and did the job so it would give it time to really work in.

The morning after I got the part, I sprayed some more PB Blaster on it then reached down and back up from the top right side and was able to unplug fairly easy.

Next I found that 7/8in boxed end wrench fit on it nicely. so I threaded the wire through the boxed end then proceeded to lean on it as hard as I could but it didn't budge. So I went back online and read a post by someone saying to run the engine for 5 minutes then try again. Well I have to say that was some great advice as it came loose so easy I almost hurt myself...lol. I was able to unscrew by hand the rest of the way...pretty cool.

Once I got it out I just had to screw in and tighten the new part and plug it in. The code should clear itself after you start the car.

Another quick note: They say to put never seize on the threads but the part I got already had it applied.

Reply to thread if you have any questions.

RexG