Map sensor

[ald872000]

I got a question that is puzzling me

I got a 1990 crown vic LX stock 302 engine

I was at a junk yard and I see a tube connecting from the plenum
To the MAP sensor on almost all 5.0L engines.

Now what I found out in my Crn Vic is that the tube from the Plenum to the Map sensor isn't there. I snooped around with a mirror and flash light to see If I might have a vaccum leak but I found that SOME ONE PLUGGED IT with some kind of rubber stopper.
Now I live in california and I did some research and I get this:
"The Manifold Absolute Pressure (MAP) sensor is used on the 5.0L engine, except on 1990-91 sedans sold in California"

My question is: should I install the rubber tube from the Map sensor to the Plenum or should I leave it as is?

(did a Check Engine light Diagnostic got code 22 {MAP/BP sensor out of self test range.} But I guess it's throwing that code b/c the tube isn't connected. Also I'm getting a funky idle that may be a cause of the tube not connecting to that Sensor