Where / how do I get to the O2 sensor?

[Markw]

This car desperately needs an O2 sensor. The exhaust smells terribly of unburned hydrocarbons, and I'm afraid I'm going to plug the cat if I don't get the sensor replaced. I have a crappy Chilton manual that shows me generically where it is, but I can't find it to save myself. The car is an '89 V6.

While I have your attention, can anyone tell me how to easily (if it can be easy) change the rear bank of plugs?

Thanks to all for any information you can share.

[Tercel GTS]

there is prolly 3 on your car
I'm expecting one in each exhaust pipe directly under the manifolds, and another in the pipe after the 2 join as one

[Toysrme]

There is one on each exhaust manifold, and one right behind the cat.

If it's the one behind the cat giving you trouble it's a bitch. You have to take atleast your passenger & sometimes the driver's seat out to get to the wiring.

[mcelligott]

If youre not throwing a check engine light, the o2 sensor(s) are probably ok.