R1 air/fuel guage

[Mikealj]

I am trying to hook up an R1 air/fuel guage to a WRX. The directions say to splice into the wire goin to the O2 sensor. The only problem is that there are four. I am pretty sure that it is the white wire, but when I connect it I get a reading of rich. It won't even move. Also, when there is power to the guage, and the wire to the 02 sensor is not connected, I get the same reading.

Can anyone help?;UgH:

[WhiteWorx]

Nope, cant help ya. Wish I could. But I hope you figure it out so it will work in my damn car.

[Slava]

On my sensor it was the purple but I have a honda.

[STIBungy]

The white wire is the right one. Are you connecting it to the front O2 and not the rear?

[rmcdaniels]

I've only done this a few times, but here's what I found:

The four wires are for the following:

heater
heater
signal
signal return

In my experience the heater wires are the same color (usually either white or black). I've hooked up the gauges to the signal return before with no ill effect, other than that the gauge didn't work, but I didn't blow anything up, I just had to hook it up to the other wire to get it to read properly. The other thing I've found is that (per the instructions) you should make sure you get the ground wire of the gauge to a good engine ground. I run it back into the engine compartmenty to get a good ground. The last one I installed (on my Honda) I just put inline connector clips (make sure the wires are not shielded) on both of the wires that were not the same color and tried each.

What colors are your four wires and who is the manufacturer of the sensor?

[rmcdaniels]

good point about front vs. rear

[WhiteWorx]

We have it hooked up to the white wire on the front sensor (exhaust manifold O2 sensor) There are 2 black wires, a blue wire, and a white wire. Mikeal took a light tester and found the white wire to be the return. I know my car is running rich, but there is no way it is running so rich that the guage doesn't lean out at idle or when the turbo kicks in.

When I turn my ignition to the first click where only the wipers and radio work (no windows, no headlights, no fuel pump or injectors), the guage will sit in stoich. But, when I turn the key to where the headlights come on and the injectors prime, it goes all the way up to rich and stays there.

Could we have a bad ground or a short where we spliced the wires together?

[rmcdaniels]

If the white wire is the return, shouldn't it be hooked to the signal wire (the blue one)?

[WhiteWorx]

No, as I understand, you want the guage to read the return voltage from the sensor. I may be wrong though? Please let me know if I am wrong.

[stu]

I'm having issues with my A/F guage as well, but it's because I used a tap on a shielded wire. I'm getting it fixed today though. :)

[rmcdaniels]

I don't think you want the return voltage. This is basically the ground for the sensor, but I don't like to call it a ground because it may not go directly back to the same ground as avarything else in your car.

[WhiteWorx]

I guess I will try to hook it up to the signal wire. I will also have to check the ground. The more I think about it, I think I might have a ground or voltage issue.

Any other suggestions?

[Mikealj]

yea I am using the O2 sensor in the front, I will try the blue wire and check the ground later and see what happens. Also, is there a way to hook up an EGT guage to the stock sensor?

[rmcdaniels]

I don't think so, the stock sensor uses a ceramic element that detects unburned hydrocarbons, whereas an EGT gauge is fed by a thermocouple.

[STIBungy]

Where are you tapping the wires? On the O2 sensor itself, on the engine harness, on the ecu? I know that has nothing to do with your A/F readings.

[Mikealj]

I was tappin the wires right after the sensor. As for the egt guage, I did not mean off the O2 sensor, but I thought that the WRX had a stock exhaust temp sensor that went to the ecu. I might be wrong about that though.

[STIBungy]

This article seems to answer it all:

http://forums.nasioc.com/forums/showthread/t-397663.html

Should be connected to the rear O2 sensor, why, I dont know.

[rmcdaniels]

from the info on that forum it looks like the WRX front sensor is a wideband unit, but only a limited range wideband unit or it would have five wires. the rear sensor is a narrowband unit, but it will give skewed results due to the action of the catalytic converter. The narrowband AF gauges really only give an indication if you are close to 14.7 AFR anyway, so it's not like you can use them to tune. I use mine purely as an indicator that I am not running lean under boost. It looks like you're screwed on this one, unless you want to drill a hole in your exhaust and weld an O2 sensor bung into it. I did see some references to using an EGT meter with the WRX, so it may have that sensor already.

[WhiteWorx]

Thanks for the info guys. I totatally forgot about wideband. I have cat-less exhaust, so I will probably try to hook it up to the rear sensor.

I wasnt planning on using the guage for tuning, just to see the running condition under boost.

Thanks for the help!!