Hey Guys

Sorry updated to 02 sensor

My 02 is in but then the plug is out I have no idea where it goes or if its needed, on the APEXI is shows nothing for it, cant be good.

But I want to hook up a guage so I want to know how to wire it, or at least plug it in.

Can some one check on there car and let me know?

You attatching an Apexi AF meter and turbo timer?

I got the ecu diagrams for attatching the wires etc.

But Im guessing you removed the plug from the sensor and lost the plug?

Hey Nick

I had a look at the wiring diagrams 2 for heater 2 for sensor so i need to know the one for air/fuel meter not apexi some cheepy haha.

After installing guages we looked to find where the o2 sensor was and noticed it has never been plugged in ever! so i need to plug it in and tap into it for the guage

Any one got a pic of the underside of a tez showing the o2 sensor? pretty please

Just into the front pipe of the exhaust, take a look at the picture I got for my front pipe:

Is it a wideband or just a narrowband sensor?

If its wideband you may need a wideband controller, something like a LC-1 Lambda Cable

LC-1 Wideband Controller

Unless the engine management can control it?

Haha thanks alot guys im sure its the standard one and nick the picture of your pipe is great but its where that plugs into is what i need to know :)

Are you after where the wires from the O2 sensor plug into car?

I wired up a air fuel gauge on my car and the wire comes in from under carpet on passenger seat under glovebox and plugs into a plug beside all the fuses on left side under glovebox.i'd have to check again but from memory i think i tapped into the blue wire.

Yeh mate but every thing looks standard but i think it was never plugged back in after the transplant the wire looks a bit short to go all the way up there

Does this help?

Fantastic thanks alot finny im sure I will just be able to get a adaptor for that plug if i can find where it goes to on the underside of the chassisI will have a look at it soon

Where would i get one of those plugs from

Are you getting a CEL light without it plugged in? Your cars Turbo right? It would only be useful for off boost/closed loop. Dont think a A/F guage would work with it since its a narrow band and only outputs 0-1v. 450mv being stoich, less than 450mv lean, more than 450mv rich.

You can wire it directly into the ecu if you cant find the plug, the wires on the ECU plug are as follows (SXE10):

Red/White = HT Signal
White = O2 Signal
Brown = Earth
Black/Red = B+



The O2 signal wire should be a shielded wire, I.E. with an earth shield to prevent interference. If you O2 sensor has a plug with a loom on it then it should be pretty straight forward.

Yes its turbo, do you think it would use more gas if its not plugged in? I have sorted out the wiring , for it and the plug.

Thanks for that information damn so a air fuel meter wont work any way or can u get narrow band af meters

Most cars factory standard will have a narrowband o2. I dont think you'd be able to hook one up to a guage or anything but may be wrong.

Aftermarket widebands often have a narrowband output (0-1v) and a wideband output which would be suitable for a guage or aftermarket engine management.

If your doing a long trip an o2 will improve your fuel economy, it will keep the fuel mixture perfectly stoich (14.7:1 -- 450mv). But if your boosting around town I dont think you would really notice much.

It would only be useful for closed loop (partial throttle, low revs) otherwise it will be reading injector duty/duration from a fixed map in open loop. The factory ecu will make long term fuel trims to the map, but usually this wont matter too much.

Another thing, if your going on boost with a piggyback ecu, then when your piggyback tries to dump more fuel for the spooling turbo, the factory ecu will read the o2 sensor as reading rich and trim the crap out of your setting. This will cause lean out when coming on boost, mainly in part throttle.

You're wrong, but only kinda...
You can install them on a narrowband O2, but they tend to just swing wildly from rich to lean as you sit on the gas or off it.

a mate had one, they're ok for wank factor(like A pillar or external gauge mounts), but thats about it.

There wouldnt be much sense, an O2 sensor never returns 0.45v. It will sign wave from about 0.2v to about 0.7v and back again, the average would be roughly/close to 0.45v.

There isnt really much of a point :)

Cool good to know , I wonder how much this differs with the apexi power fc

none... same sensor, same signal, same fluctuation.

I'll have a look through the power FC tonight and see if it allows you to change the sensors, some of them(AFM/MAF) it seems to accept alternatives.

Dont know if it has compensation for an alternate sensor to output factory voltages, but you should definately be able to use any AFM on the PowerFC. You'd just need a return I'd imagine.

I was running a RB20DET AFM using my Emanage Ultimate. As simple as snipping the B+, Earth, Signal wires and connecting them to the new AFM.

Was running without an IAT sensor though

Still in this topic lol , Can you get narrow band gauges? have got it all wired up and it does save on gas!