O2 sensor bung Reply #15 – May 11, 2018, 09:36:20 PM yeah,, thats what i was trying to say but since you brought up the technicality of the orange wire,,, that would make it a 4 wire thingy but they are actually 3wire. Quote Selected
O2 sensor bung Reply #16 – May 11, 2018, 09:38:43 PM on 87 & 88 cars the orange wire is under the braided cable on the driver side which is attached at the fire wall just next the the accelerator cable.so the orange wire belongs on the fire wall, not the head.te braided cable is on the same spot on the fire wall and lands on the rear of the driver head.same point electrically but just sayin..... Quote Selected
O2 sensor bung Reply #17 – May 11, 2018, 09:58:47 PM Interesting...the tbird-cougar is different? I've always seen the mustangs either to the back of the head or the rear lower intake stud ( mine). The Turbocoupe has it on the turbo compressor housing. I've never seen it paired up with the braided cable to the firewall.John Quote Selected
O2 sensor bung Reply #18 – May 11, 2018, 11:14:49 PM When I got my car, it was already a Mark VII HO swap. engine, trans, exhaust; which included the EEC and complete engine harness, so some things on my car don't conform to T-Bird/Cougar wiring books. My orange wire goes from the EEC to the back of the head, then from the back of the head to a splice and to each HEGO, and mine are 4 wire, as far as I can tell, not like T-bird/Cougar or Mustang. Or really even like Mark VII books. When I lost the HEGO sub harness during my last build, I had to build a new one from memory and that's how I built it. Quote Selected
O2 sensor bung Reply #19 – May 12, 2018, 01:23:10 PM Quote from: jcassity;465724on 87 & 88 cars the orange wire is under the braided cable on the driver side which is attached at the fire wall just next the the accelerator cable.so the orange wire belongs on the fire wall, not the head.te braided cable is on the same spot on the fire wall and lands on the rear of the driver head.same point electrically but just sayin.....My 88 is set up this way. I did add a ground wire from the ground point on the firewall to a stud on the back of the intake. Didn't seem to make any difference but it makes me feel better :hick:. Quote Selected
O2 sensor bung Reply #20 – May 12, 2018, 09:43:07 PM now,, to let the juice out....i do not believe ford connected this 4th orange wire correctly from the factory.the orange wire is provisioned with a lug able to take a 1/2'' bolt. that would mean that it should go on the rear of the head.... but im betting heat and the insulation ratiing i saw would not put up with that very well. Quote Selected