Which wire on O2 Sensor for A/F gauge on 97-98 240

[180PWR]

Which wire do I tap into on the O2 sensor for the A/F Gauge ? mine has 3 wires.

[Ritz S14]

If you have access to the plug, it's the one in the middle. Make sure it's connected to the O2 before the cat, and not after.

[180PWR]

what do you mean the one before the cat? arent they both? im assuming i have to tap into the primary O2 sensor which is the one on the exhaust manifold correct?

[Ritz S14]

The second o2 sensor is to monitor your cat on OBDII cars, it's not really an A/F meter. But yeah the primary O2 on the ex. manifold. Didn't meant to confuse you.

[180PWR]

Theres 3 wires.. And there in a triangle formation there is no middle.. 2 white wires and one black wire

[Ritz S14]

It's the black wire. The other 2 are your heater wires. SOrry I'm reading this from the wiring diagram, and it's in the middle.

[-usmd-180sx]

sorry to bring up a thread from the dead.. i hate it myself.. but its for a good cause :boink:

anyhow... i recently installed a new outlet pipe and i had to change o2 sensors.. to make a long story short.. my new o2 sensor's wires are TOO short to reach the connector under the hood.. and i guess i have to splice my old o2 sensor(skinny) wires to my new o2 sensor (fatty) wires to elongate it to reach the connector under the hood..

here are some pictures to help u understand what im talkin about

https://home.comcast.net/~180sxdrifter/Picture_001.jpg
https://home.comcast.net/~180sxdrifter/Picture_002.jpg

the harness on the right in both pictures is the stock o2 sensor connector..

What i need to know is what wire does what.. and how i should splice the wires... could anyone clarify on how i would splice connector A(left o2 sensor[fatty]) with the wires on the right(old o2 sensor[skinny type])

thanks in advance

PS.. this is off a s13.. and the o2 sensor on the left is a Bosch 200sx 1.8 T o2 sensor.. and the one on the right is a stock redtop "skinny" o2sensor

[Ritz S14]

Just splice them and attach them in the same order.. 1-2-3 goes with 1-2-3. It's somewhat fool proof, just make sure you have the black on in the middle, and you should be okay.

[-usmd-180sx]

Just splice them and attach them in the same order.. 1-2-3 goes with 1-2-3. It's somewhat fool proof, just make sure you have the black on in the middle, and you should be okay.

lol.. i thought something along those lines.. but i wanted a second opinion.. i also knew the black goes to black.. and im sure black is ground correct? can anyone third this opinion... 1-2-3 goes 1-2-3?

i'm not saying your wrong.. i just dont want to go :faint: in the long run

[Yoshi]

tangent:
what kind of A/F gauge did you get?
Unless it's a wideband it'll be for bling value only.
A/F Meters, especially the autometer ones, are worthless on our cars :/ They only read at WOT, and even then you'd be foolhearty to use it as any kind of diagnostic tool. Your nose is a better A/F gauge ;)

[90sr]

this is tru, i tried splicing my a/f gauge into all 3 color wires on my o2 and one read lean one read rich and the other one didnt read any thing, right now its on the white wire and reads rich but i know im not really rich, good luck its a useless gauge.

chris

[Ritz S14]

The one that read nothing is probably heater ground, the that read rich is probably 12v heater. Try leaving it on the one that reads lean, and drive it around for a few minutes.

[90sr]

aright sounds good ill try that see what happens, i also thought it might have been my cat, since i still have the stock cat on there so thatswhy i thought it read rich but i duno thanks.

chris