Greetings all. This my first post here. I'm the new owner of a nice 86 2.8L SE. It has no oxygen sensor. There's a hex fitting with flats about 15/16" apart (24 mm) on the exhaust pipe where the sensor should go, but no sensor or wire. I poked a piece of wire into where the sensor should be, but it's just a hole now that is letting exhaust gases out!

My questions are:

1. Do I have no sensor at all, or is the base of an old sensor there and the rest of it broken off?

2. When I install a new one, where does the sensors wire plug in? Pictures for this?

3. Would this be a one or four wire sensor?

One wire

The wire should be running off of the harness right there.

The hex thing on your exhaust is 1/2 of the O2 sensor. It needs to be screwed out.

[This message has been edited by phonedawgz (edited 06-02-2011).]

When you say "off of the harness right there", I looked at the harness and didn't see a plug coming out of it in that location. Should there be? Where on the harness?

Do you mean the catalytic converter being blocked? If so, what does this mean, that it won't run with an O2 sensor installed? And that the catalytic converter will need replacing?

quote Originally posted by phonedawgz: One wire The wire should be running off of the harness right there. If someone took the O2 sensor out that might be because the exhaust system/cat is blocked.

I thought maybe the previous owner took the O2 sensor out to bypass a blocked exhaust. Now that it looks like the O2 simply failed, I don't suspect the exhaust is blocked.

[This message has been edited by phonedawgz (edited 06-02-2011).]

Situation resolved. I found the old sensor dangling from its wire. It had fallen apart and it's six sided base was still screwed in to the exhaust pipe. Was able to remove that and install the new O2 sensor.