hey i was going to install a narrowband air fuel gauge in my 94 lx. just so i can keep in eye on things. which o2 sensor do i tap, i have on on my headers and one right before the cat

 

The 94 should have only one sensor. Was there some kind of modification done to the car (like an EX engine installed)?

 

not as far as i know. the other sensor is at the end of the downpipe right before the cat, maybe its a different sensor?

 

Here's a picture of the EX exhaust. The EX manifold is a 4-into-2 configuration, so the A-pipe (#8) is a 2-into-1 configuration. The stubby little pipe (#7) just before the cat looks like it might fit interchangably between EX & LX. So maybe it's only that little pipe that comes from an EX??
What you think is your "rear" sensor could be #31 which is supposed to be the one & only sensor in a 1994 EX. The OBD-2 rear sensor (#32) is only used for 1996+ cars so you shouldn't have that at all.

So if you have an LX, with a 4-into-1 exhaust manifold, your active O2 sensor is in the exhaust manifold up front. The other sensor in that little #7 pipe probably has noplace to hook up electrically. Unless the sensor itself is bad, maybe you can use that one to avoid signal crosstalk with your ECU.

 

wow, cant tell you how much that helped. i installed the gauge and wired it no problem, but it a little on the rich side, not full rich but its commonly just on the line. any ideas to fix this? i know its not the o2 sensor because i changed that about 200 miles ago. maybe the MAP?