onmy firewall where the map sensor is, there are two plugs. anyone know what the second plug (not map sensor) goes to and what it does? (looked it up in helms but it doesnt show it)

also ive noticed some cars only have one of those black cylinder things next to the map sensor on the firewall, and some have two. whats the difference?

 

Purge solenoid. It's a rather important emissions device, from what I gather. I have an obd1 IM so mine is now mounted on the IM, I have a spare firewall mounted solenoid if you'd like it.

 

use the one on the firewall will work with obd1 swap if you have the jump harness from obdo to obd1