i have a hf manifold and i plan on taking my car to a dyno with wide band should i put 2bungs in the dp or 1in the manifold+1in the dp where is the best place for the sensor to the ecu

 

if it's a d16y7 i would put the primary in the hf manifold...the original y7 manifold places the o2 there. when i had my primary at the end of my header when i was n/a it took much longer for it to warm up and would run extremely rich and bog until it did.

basically i would mount it wherever it is stock...if it's in the top stock, mount it there. if it is under the car stock mount it there.

as for your wideband sensor mount that at the end of the downpipe before the cat...or testpipe if you are running catless.