HI,

Its built into the fuel pressure actuator , attached to the fuel metering unit.
has 2 screws holding it in place, once removed, you have a brass screw usually,
and you remove this to expose a allen type key this alters the fuel pressure
some are more sensitive than others in my experience, bit fiddly and trial and error
as i remember screw in to increase fuel pressure, a quarter of a turn at a time
then reassemble and check co%, at idle and mid range 3500rpm, approx on chipped car 2.5%idle and 3.5% at mid range, if you dont know what your doing
let a pro do it and setup.

DAVE R.