First off, I have no cat. Could I use the rear O2 sensor for my A/F gauge? Would there be any problem with the reading from the sensor because it is located farther down the exhaust pipe? I also have the resistor mod to get rid of the CEL so I would have to tap the gauge into the signal wire before the resistor. The reason I ask is because it will be alot easier to hook my gauge up. I wont have to bring this one trough the firewall.

BTW, can we use the O2 signal wire ground as a ground for the A/F gauge?

-Jared
96 GS
Melbourne, FL

The rear o2 sensor just checks to make sure the cat is there and working.. therfor I do not think you want to use it. I tapped into the wire at the ECU. (black with white stripe I think, might be the other way around)Going through the firewall is not hard, there are plenty of places to go through.

just to metnion it is white with a black strip. and the fire wall thing just drill a hole above your pedals theres an area in the engine bay side of the firewall w/o anything there. Just make sure to use a gromet so that the sahrp metal doesnt wear away the wires protective jacket.

oh sorry , about the rear 02 resistor mod, i have that at home so ill give you the specific info on that later.

Be careful where you drill into the firewall. Check on both sides to make sure that the drill bit wont go into anything else. Above the pedals can be a safe place, but just remember that the brake booster is right there also, and if you drill into that then you will have to replace the whole thing.
Just a thought,
Chris b.

where is the info on the rear o2 mod? I never saw that, I knew it was discussed. Is it on the main page?

http://www2.cesa12.k12.wi.us/brent/personal/neon/pic/cat_resistor.html