It's the time of the year again for smog. My brothers rt4wd is completely stock. He at one point hit something on the road that had his exhaust manifold cracked. So last year a y8? Manifold was installed and was cut off after the runner turned 4 to 2. Then it was custom from a muffler shop to clear the trans gear box of the rt4wd. Drove like that for awhile with the o2 sensor not plugging into anything.

So my question is, since I'm welding an o2 bung in for him, where would the o2 sensor sit at? I didn't want to put it on just one of the runner of the y8 header. Could I weld it before the flange to the cat like b series header? Tia

 

No one?

 

Pretty sure a one wire O2 sensor needs to be closer to the head. A 4 wire sensor would be fine down there.

 

yes, its obd0 1 wire. i saw how the a6 mani has the o2 where all the runners came together. on the y8 manifold, the runners are all individual then to 2, then one under the car. would it be ok to weld onto 1 of the runner? does anyone know if an a6 top half would fit a y8 lower half?