Needing info on Differential Pressure Regulator

["Michael Theuri" <mikesoft@europa1.conwaycorp.net>]

I hope I got the description right. My mech. says he
pulled an engine code that indicated my differential
pressure regulator is malfunctioning. He says that this
has something to do with my idle problem (esp. at stops)
in addition to my cracked ISV hose ( I ordered one from one
of the dealers on the audifans web page and I have already
called them once and its now going to week 3 and no show
yet). He says it works in conjunction with my Oxygen sensor.
Is it hard to replace this regulator ? Does anyone have the
procedure ? Is this a pricey part ? Thanks

Mike Theuri
88 80Q