yes, but you don't have to take the downpipe off to have a bung welded in.

 

nope... you could put the bung facing to the passenger side as well, just have it ever so slightly pointing down.

 

I always install Wide Bands with the wire going through the same place as the factory 02 sensor wire. If you pull out the passenger seat you can see there is a slot in the carpet, underneath it there is a small hole that you can run the sensor through and then just cut the rubber boot a tiny bit to allow it to be used again with extra wires in it. This way I can leave the LC-1 controller or whatever unit I am using underneath the carpet under the passenger seat. It makes your wiring extremely short and keeps everything nice and neat. You do have to enlarge the hole a TINY bit to allow the sensor to pass through easily, a dremel works great.