7 replies to this topic

[Bmxgt]

Hello people, i'm wanting to re-wire the 02 sensor (99gt forester) from the stock one to the AEM air/fuel gauge sensor.

So what i'd like to know is what wire is what on the stock sensor.
3 wires white, white/black strip and black.

Gauge sensor wires are grey, red, black, yellow and white.
But the colours and amount of wires change after a plug, they are green, red, brown, white, black and orange

I've spent some time on google and have come up with nothin. Could someone please help label colours to match together.

Cheers

[Reevesy]

Cant help with the colours, but wiring the stock narrowband sensor into a wideband guage (Im assuming) wont work as the voltage outputs are different.

 

Would need the matching AEM wideband sensor to use it. (AEM has 3 different sensors)

[Bmxgt]

Sorry no. I want to wire the AEM (wideband yes) sensor into the ecu. And ditch the stock one. I'm farely sure the stock sensor is rubbish.

Laptop says target a/f is 14.7. But gauge sits at 13.1 down to 11.4 when cruising. 10 at WOT

[RX25SE]

As above, wont work.

 

Stock O2 sensor is a switching type that switches between 0.1v (lean) and 0.9v (rich) when it reaches about 300degC and the ECU monitors this voltage. It can have between 1 to 4 wires depending if it is heated, runs an external earth or both.

 

The wideband A/F ration sensor has 5 wires and uses current to artificially hold a chamber in the sensor at 14.7 AFR (Lambda 1) and the ECU monitors current (sometimes a scan tool will display a voltage) in or out to determine the actual A/F ratio. In addition they require a driver circuit in the ECU and have a laser etched calibration resistor in the plug to set a reference point in the ECU.

[Bmxgt]

So i should just buy a new 02 sensor and see if it works the same or better.

Thanx for the help.

[RX25SE]

Sounds to me like it is working, just the engine is rich.

 

A faulty sensor will often display a correct voltage, just cycles (cross counts) slow.

 

Can you graph the sensor?

 

I'm thinking that there is another issue here and replacing the sensor may just confirm that it is not at fault.

[Bmxgt]

No idea what you mean by "graph the sensor"

Its pretty much been like it since being tuned. May be slightly "richer" now.

I hope to get it retuned in a few weeks. May leave it to a pro to figure it out.

[RX25SE]

It means show the O2 voltage against a time scale.