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Can anyone show me where the stock s4 88 T2 o2 sensor wire is located on the factory harness or where it comes out of? I have tried to look everywhere from videos to used harnesses online and i can't find it on mine.
i think my original connector is broken or cut off but i want to find where to splice into. The screen shot from the factory wiring diagram shows it's connected with the ACV loom with a grey wire but mine had a hidden thick white wire that when connected according to my Rtek 2.1 with a brand new Bosch sensor does nothing, no values.
the O2 wire likes to snap off very short there, since it sits right above the baking turbo exhaust. it's a 2 layered grey and black sheathed wire with a grounded shielding insulation layer.
you have to be careful splicing a new connector because if you bond the shielding layer with the sense wire it will pull the signal to ground, basically meaning the O2 signal won't make it to the ECU.
Last edited by notanymore; Apr 5, 2025 at 08:58 AM.
the O2 wire likes to snap off very short there, since it sits right above the baking turbo exhaust. it's a 2 layered grey and black sheathed wire with a grounded shielding insulation layer.
you have to be careful splicing a new connector because if you bond the shielding layer with the sense wire it will pull the signal to ground, basically meaning the O2 signal won't make it to the ECU.
Thank you! That's exactly what i ended up doing, i was wondering why the wire was so big when crimping on the connector haha. I stripped it back to the black wire on the inside and it looks like it's getting some kind of signal output now.
