upstream o2 sensor issues

[Dayonaise]

So here's the deal, bought a 97 tsi awd with a 90 6 bolt swap. Runs great until about 4000 rpm then bogs hard, so i had a look around and found there is no o2 sensors through the 3" straight piped exhaust. Now my issue is i have read that i should install it 36" from the exhaust port on the turbo and i have also read i can just use the stock location because its not a wideband system just a stock sensor. Is this correct?
Also i have not been able yo find the o2 harness anywhere i do know what the 97 harness looks like but no idea where its supposed to be and yes i have searched countless threads and sites. And I'm unsure if I'm looking for a 97 harness or a 90 harness because of the swap, are they in different places? I appreciate all the help i can get thanks.

Oh and i do have an autometer AFR gauge that as far as i can tell is not wired in or has been snipped

 

[WES_393]

Glad to hear a new O2 sensor solved the problem! Thankfully the wiring harness wasn't hacked to bits like I feared.

As for your EQUUS A/F ratio gauge, it's definitely a narrowband gauge. It's supposed to tap into the stock O2 sensor, so that's likely what those wires are for (along with power/ground for the gauge). Since the gauge won't tell you an exact A/F ratio like a wideband it's pretty much useless. I would remove the wiring for the gauge and repair any wires they were tapped into. Then put a wideband on your Christmas list.

 

[Dayonaise]

Yes wideband is on the list for sure haha, and I'm going to switch both boost and af gauges to digital aem ones i really like the aem truboost gauge also getting a ext temp gauge.
I am going to change my coolant temp sensor tomorrow cause its throwing a code 0115, hopefully that fixes my bogging issue

 

[Insane20]

now say if you didnt have the down stream o2 pluged in, could that cause any issues?