How to extend the O2 harness for long tubes?

  • Sponsors (?)


Use 16 gauge wire for all the wiring and you should be fine. The O2 sensor is the only thing that draws any power, so it needs the 16 gauge wire. The O2 signal wiring can be 18 gauge. The key thing is to use Teflon or high temp insulation wire to avoid heat damage to the wiring. Using all one gauge wire makes the job a little simpler to get the correct high temp or Teflon insulated wire.

Keep in mind that the O2 sensors need to be as close to the exhaust port as possible. They need heat to work properly, and long tubes lose a lot of the heat needed to make the O2 sensors operate correctly.
 
The wires go way forward by the rack, then up, then all the way back to the 10-pins. You can simply re re-route them down the back of the motor and buy yourself more than enough length without having to cut, solder, crimp, or insulate.
 
The wires go way forward by the rack, then up, then all the way back to the 10-pins. You can simply re re-route them down the back of the motor and buy yourself more than enough length without having to cut, solder, crimp, or insulate.

they had no chance of reaching, it was about 20in too short so i started cutting and extending yesterday.
 
They have every chance of reaching with length left to spare, if you simply re-route them, unless you're putting the O2's back by the mufflers.

ok if you say so, i pluged the harness to the plug and even if i ran it straight to the plug across the header they were way to short. if it could be done without cutting it would be on the car. i have bbk 1 3/4 long tubes and my o2's are under the floor pans.
if they fit why do companys make/sell extentions?
 
I'm with MFE92, I have 1.625" BBK long tubes, with the O2 sensors just before the collector, under the floor pan on my 89 Mustang, and I rerouted the existing wires and they are just long enough to work. They've been in place like that for 12 years now. I moved the engine back 1" a few years ago, and they still reached fine.
 
Good question, and I can't remember for sure, it was a long time ago. I went out and looked at it, and it's in black plastic tubing almost the entire route, but I could have added that at the time. I ran it under the motor mount on the passenger side, and I believe originally it was above the motor mount. From there it runs in a straight line to the O2 sensors. I tie wrapped it to anything convenient along the way. Pics would be tough to get underneath. Good luck,