bout to hit the road. at work. new denso O2s just came in. Advance auto next door . .

[cordrayj1]

ive got my tools. is it absolutely neccessary to have the O2 socket? looks like this is a breeze. wanted to do it before i left so i can see the difference in G-mileage

 

[blcktpgsr]

Not really necessary..I recently replaced my front ones using a nut driver with a 14mm socket..either 14 or 12mm. But no special tools required.

 

[bak3rme]

if u got no rust should be easy. just pb blast it and let soak for a bit if no rust. no special sockets needed

 

[T4R_Finally]

You don't need an O2 socket for 3rd gens. They are bolted in on either side using what should be 12mm nuts. They can be a PITA to get off if there is corrosion. I PB Blasted mine 24 hours before and again just before trying to remove mine and I couldn't get them to budge with a standard 12mm socket. I went and borrowed a 6 sided 12mm socket (inside shaped exactly like the outside of the nut) and it grapped them and they came right off. I'd recommend new stainless nuts and some anti-seize when you reinstall though. I couldn't find any at my hardware store, so I went with 13mm stainless nuts with stainless lock washers.

 

[TheDurk]

You don't need an O2 socket for 3rd gens. They are bolted in on either side using what should be 12mm nuts. They can be a PITA to get off if there is corrosion. I PB Blasted mine 24 hours before and again just before trying to remove mine and I couldn't get them to budge with a standard 12mm socket. I went and borrowed a 6 sided 12mm socket (inside shaped exactly like the outside of the nut) and it grapped them and they came right off. I'd recommend new stainless nuts and some anti-seize when you reinstall though. I couldn't find any at my hardware store, so I went with 13mm stainless nuts with stainless lock washers.

Yes, except 2001-2002 the rear socket is the screw-in type, not the flange type. For those years, an O2 socket would be helpful.

12 and 13mm would be the wrench size. The size of the nut is M8-1.25. Or Toyota part No. 90179-08059 if you want OEM.