air/ fuel gauge

[tony/ka24de]

I'm putting an air/fuelautometer gauge in my 1997 240sx. On the gauge there is three wires red(power),black(ground),and purple(signal) (Is this right?) Now , does anyone know which wire the purple one connects to on the O2 senser? there are three wires on the O2 senser.

[syco3d]

good luck with the autometer a/f gauge...everyone around here says autometer is the shizzle EXCEPT for the a/f gauge...but who knows. :D

yes I know my post is pointless...I'm bored. Really really bored.

[the head]

why do people use these things they are of no use at all plus they suck

[HaLo]

I bought one, installed it and it was a huge waste of money i could've put elsewhere.

Do a search on the KA24DE ecu pinout. You'll find your wire.

[tony/ka24de]

i never asked anyone what they thought about the gauge, I just want to know where the wire goes. I will run the wire out to the 02 senser if i have to. but don't know which wire

[the head]

refer to above thread and search for wireing diag or ecu pinout

[HaLo]

Find yourself someone that has a KA24DE FSM and check the ECU pinout!

[Rownan]

I recently installed an autometer A/F gauge in my S14 and while it isn't the most accurate device for tuning, it is a cool little gizmo and is more useful than what people say...

O2 signal is a solid white wire at the ECU, pin 46. That's where I hooked mine up at.

[tony/ka24de]

the 1995 has a different o2 senser, it is a one wire o2 senser. the 1997 has a three wire o2 senser. I also think the computer is different.

[s14slide]

Originally posted by tony/ka24de
the 1995 has a different o2 senser, it is a one wire o2 senser. the 1997 has a three wire o2 senser. I also think the computer is different.

wrong buddy, I have a 95 w/ an autometer a/f gauge. The first O2 sensor has one wire and the second O2 sensor has three.

I hooked up my gauge to the first sensor(closest to head) and used the ecu pinout on 240sx.org. I hooked my purple wire right by the ecu, and used the power wire to the ecm because it's constant and it's only on when the ignition is and I used the ground point used by the ecm. Works like a champ. Just takes a few seconds to warm up on cold days. Hope this helps.

[ChillyWilly3]

Actually, tony/ka24de is right.

Like S14slide said, the 95 model uses a one-wire front O2 sensor and a three-wire O2 sensor in the rear, but the 96-98 models use three-wire O2 sensors on both the front and the rear.

I own a 96 240sx and just recently installed an Autometer A/F gauge and ran into the same problem. I'm not sure what color-coding you have on your 1997 ECM for the front O2 sensor, but mines was blue, white, and brown. The blue and brown wires are the heater wires. The white wire is the signal wire. To be consistent I guess, Nissan kept the white wire (O2 signal wire specifically) on ECM pinout 46 for years 95-98 (KA). That's the wire you need to attach the purple wire to.

What I did was I extended the purple wire into the engine bay and tapped into the front O2 sensor connector white wire (ECM side NOT the O2 sensor side!). I tapped into the 12V lighter socket for the red wire for ignition ON power and grounded the black wire to a metal part of the chassis just under the steering column. I also attached an on/off switch so that you can turn it off when your not using it or when it begins to annoy you at night time. :p
Good luck!

[tony/ka24de]

Thanx a lot man