Been doing a bit of research and other then problems with the clutch slave, fuel lines, and offroading clearance not many people have had a problem with running the crossover under the trans once you re route everything.

I already have my 3.4 installed with a thrown together crossover but i'm pretty sure its cracked somewhere and would like to improve on the design/flow without buying a header and cutting it up.

Do not have a rear o2 sensor already so that wont be a problem only thing i'm worried about is the fuel trim readings from the upstream o2 sensor affecting the way it runs.
No smog here in Oregon.

Jasond did dual exhaust and had the upstream only reading off the driver side bank and seemed to run fine with -10 ltft

https://www.yotatech.com/forums/f160/22r-5vz-swap-126413/

Tons of info on the factory design x over but not to much for the other.

 

https://www.yotatech.com/forums/f2/v...14/index4.html

Swapped under and running o2 only in driver side. She runs pretty good ;-)

I run two 1 7/8" vbands on either side of the trans, and then one more before the turbo so I can unbolt the exhaust it to do trans or engine work.

 

my crossover is underneath too, but i ran mine tucked in tight in front of the trans for ground clearance.

 

I thought it would work just wasn't sure about the increased distance for the passenger bank and o2 sensor reading because of it.
Any pics?

 

Check out my turbo build thread in my signature for pics galore. I welded in a screw in o2 bung and am using a bosch universal screw in sensor. Runs awesome for 10k miles now.