If you mean:Air suspension/EVO steering module Part #9c392 it's behind right hand cowl panel, above connector bracket.
No, but you can install a spring suspension.
No, they have an air suspension which means air bags.
Yes, but it's not safe
I have a '94 and it is about 80 PSI. I imagine the '98 is similar.
No way that I know of
Best bet is E-Bay
In my 95 Mark viii there is a little access panel on the left side in the trunk, its in there. (its a little red switch.)
Clipped onto the mirror, the black box that hangs there.
No
Up under the dash, drivers side, left of the steering column
Probably one or both of the front air shocks or the compressor.