98 pre cat o2 sensor how to remove?

[laurascorolla]

Working on my daugthers 98 Corolla. The front o2 sensor is bad. Any pointers on how to remove the two 12mm nuts that hold it in. I can't get a socket or wrench on them.

suggestions?

[laurascorolla]

anyone?

[landphil]

You could try hammering an old or cheap socket onto the nuts, or if they are so rusted you can't get a socket on them, heating the nuts with a torch and using an air chisel to turn the nuts might be the best bet, provided you have those at your disposal.

[laurascorolla]

sorry, I didn't make it clear. I can't REACH / ACCESS them. Looks like the engine support and tranny mount will need to be removed. All to change an o2 sensor. Unless someone knows a tip.

[WyRolla]

I worked on mine today, had to pull the o2 to get the manifold off.

If you remove the top manifold heat shield (6 bolts), and the firewall heat shield (two nuts and a bolt), you can reach the bolts from the top. Best to use a ratchet wrench if you have one. If you don't then go buy one. Soak everything with WD-40 while you run out to buy the wrench. Don't remember if if was 12 or 14, but I think 14.

[landphil]

I'm assuming you're trying to access from below if you mention mounts, etc. but the pre-cat o2 sensor can be reached quite easily from the top, if it has cruise control it might help to move the throttle cables out of the way or even remove the actuator altogether for what it takes. I certainly don't see the need to remove any heat sheilds.

[laurascorolla]

Originally Posted by WyRolla

I worked on mine today, had to pull the o2 to get the manifold off.

If you remove the top manifold heat shield (6 bolts), and the firewall heat shield (two nuts and a bolt), you can reach the bolts from the top. Best to use a ratchet wrench if you have one. If you don't then go buy one. Soak everything with WD-40 while you run out to buy the wrench. Don't remember if if was 12 or 14, but I think 14.

that did it. Thanks for the tip.