Anyone no what the 4 wires are for on MY06 , Im fitting a gauge & need to find the “signal” wire , im pretty sure the 2 black are the heaters but not 100% ………Any help on this 1

 

3 wire sensors use the exhaust as earth.
four wires have their own. (more reliable)

just get a multimeter and probe to find the one that oscillates between 0.2-0.8 volts.

Ideally though if you are relying on the gauge for your fuelling then it needs to be a dedicated wideband sensor and gauge setup.
for eg...
WBo2.com WIDEBAND AFR/LAMBDA (Tech Edge)
or
MoTeC Advanced Engine Management & Data Acquisition Systems - PLM


Andy


Andy

 

Nice 1 Andy , off to Maplins i go

 

Got a multimeter & tested the 4 wires , now the only 2 that i get a signal from are the 2 black ones ...Now im lost

 

lnstead of connecting at the sensor you could tap in to the signal wire at the ECU.

 

One assumes you actually had it running at the time ??
or the engine was still cold thus a constant 0.8 volts (rich)


Andy

 

Jimbo - dont confuse me anymore lol
Andy - Yes mate the engine is running . right now im getting 2.84 from the blue wire & 2.48 on the white < the 2 black heaters i think , were a lot higher >
So im still lost lol

 

Both black wires are for the heater, white wire is earth, blue wire is signal,
To test bare a bit of the blue wire and connect your AFR gauge signal wire fire up the engine, with a cold engine your gauge will show a constant green meaning running rich, when warm LEDs will cycle up and down until your at full throttle when again should show green.