i think you are suppost to but them as far back as possible.

here is my setup: pacesetter long tube headers, pacesetter off road y-pipe, 3 inch exhaust going to un known muffler then split into duels and out side of truck with tips before rear tire.

i am also planning on FI, sts style in front of the muffler.

so here is my options,
1. do i put two wideband O2's on the y-pipe after they meet the headers
2. do i put two wideband O2's on the y-pipe before they merge together
3. do i put one wideband O2 on the y-pipe after the two pipes merge
4. do i put one wideband O2 on before the turbo
5. do i put one wideband O2 on after the turbo before the muffler
6. do i put one wideband O2 on after the turbo and muffler
7. do i put one wideband O2 on before the tips the farthest away i can go

i kan draz rel good

 

A WB needs to be after the turbo. But if your NA right now then after the y would be fine. The closer to the front of the exhaust the quicker it can react.

 

so just put 1 infront of the muffler

 

That would work fine

 

Using two total, one on each bank, can be an advantage if there are side to side lean issues ( like the infamous #7 piston failures ). As long as you are not running cats ( off road Y-pipe says no ) then anywhere in front of the muffler is fine.

 

I Put mine in yesterday, The aem directions say at least 18" from the exhaust port.or with leaded fuel, or turbo & High exhaust temps then 36" min. but definatly before cats or any other obstruction. Remember to put them at an angle of 10* or more above horizontal. Certainly no need to put two in a common pipe, only before they converge together..

 

Why 10* above horizontal?

 

If you mount them at the bottom of the pipe or have the tip pointing up then water/condensation/debris can collect inside the sensor and ruin or miscalibrate it.

 

so if i mount on top of the pipe then im fine

 

if you have room to sure. Here is Dynojets install packet. Look at page 5.

Wideband install