I think you meant to say "off road" H/X pipes?
My Bassani catted X has the four bungs for the sensors.

Tropic Green Y2K 5 Speed Mustang GT
P-1SC & Some MM Stuff
http://tinyurl.com/5d6dy

JS wrote:
but most aftermarket H/X pipes don't have the fittings
> for them, and thus the need to use the eliminators to keep the check engine
> light from coming on and the computer from going into open loop mode
> (reduced performance) in some models.
>
> JS