Vacuum line question

[owlpond]

In looking at some of the pics posted here (and hose routing sticky), it appears I have an extra vacuum line running from the front left port on the vacuum block, to a sensor or whatever on the passenger side fender well. Any ideas what this is?

I purchased this 85 gn used and the owner knew nothing of any upgrades. Perhaps this has been upgraded to an 87 computer? Is so, any tips on how to tell?

Thanks,

 

[SLOW_85]

The only sensor on the passenger fenderwell is the map sensor.
Maybe they tied it in there.
Should tie in off the line behind the turbo.
Check the ecm- Part # 1227148 87-ECM

 

[mybuick]

if it is a rectangle black box with 3 wires plugged into it, it is a map sensor. if it is a circle with a 2 prong connector it is the boost sensor fo the computer and the dash lights that say "turbo power".