How do you route harness from engine to trans. and o2 sensors. Stock routing looks close to my homemade cross over. Thinking about running down frame and extending wires to reach speed sensor and so on. How have others handled this would help, thanks

 

Mine just followed the transmission down the driver side. Zip tied through various unused holes. Haven't caught fire yet after 3-4 years

 

Mine was a 2000 runner engine/trans and the harness had plastic clips that attached to bolt on metal tabs. I kept that part factory original. I did wrap the harness with header wrap where it was close to my headers and exhaust.

 

I used Thermo-Tek heat wrap where it ran close to anything hot. I also have header wrap on the exhaust crossover. So far so good.

 

I DO NOT reccomend it, too much can go wrong, but I disassembled my harness, pulled the O2 sensor and trans connectors and wires out and routed them down the passenger side of the engine then up and over the trans similar to the 3.0 wiring.

Again, I do not reccomend it because the wires in the harness could not have been more tangled and inter-twined if Toyota tried, I ended up having to cut all the connectors off, pull the wires through, then re-solder the wires to their connectors. There's just way too big of a chance for something to not go back together correctly.

But this is another option if you REALLY, REALLY don't want to route the wires (with heat reflective tape!!) near the exhaust.

 

Thanks for the input my computer crashed and just got it back. I'm trying to buy harness brackets from the dealer, it not easy. they gave 4 pages of pictures of brackets and have to id them. not having backets are making this hit and miss. I built my crossover as close as I could to trans, now not sure this was such a good ideal.

 

my crossover is under the truck in front of the trans pan and behind the bell housing, but i wrapped it with header wrap and tape.
road trip tested and proven, about 1000k miles one way, no problems.
best to look at a 3.4 in a stock truck to see what you need.