Hi all, love the site. Anyway I just finished doing a 3.0 to 3.4 swap and my truck comes out of the exhaust shop today. However the damn bastards at the junk yard that sold me the motor cut off the wiring harness that goes to my 02 sensors and tranny. I was wondering can I use a wiring harness from another year and/or a tacoma one? The motor is from a 99 4runner California. Everything else is done including all the other wiring. I've already dumped quite a bit into this thing and don't want to have to buy oem and spend a crap load(I would think it would be expensive but haven't checked yet). I live in rural nor cal so finding a 99 4 runner o2 sensor wiring harness would be pretty much impossible. However finding one from another year or from a tacoma would be much easier. Any help would be great. Thanks.

 

It depends on the ECM you are using for the new 3.4...

The ECM will determine if you are wiring for A/F or O2 sensors...or 1 A/F and 1 O2.

 

So as long as the doner harness has the two 02 sensors that I need I should be good? Because i know that the 99 ecu has 2 02 sensors.

 

Yep,that's correct...If the ECM is looking for a sub1 O2 and a sub2 O2 signal....That's how you need to wire them...So you are in good shape

p.s. Do not forget to use a shielded wire for the OX signal wires(you will see OX pinout location in EWD) that go to the ECM pins,other wires can just be a regular wire.