Hi guys just a quick one, I have a boost controller on the car but while replacing injectors I’ve noticed the origins boost solenoids are still connected. Vac line from the air intake I know can be removed and plugged, however does the electrical connected to them still need to be plugged in or can I unplug it? 

The boost solenoids control safety boost not the boost pressure under normal circumstances. If you’ve still got your det sensor, leave them be. 

Det sensor has the resistor mod and one of the pipes from each solenoid has been removed and plugged, bit of a strange set up but I’m not running massive boost 

So it’s like a loop. The boost solenoid acts like a Y piece. The normal path, is from the induction pipes to the wastegate actuator with a restrictor, this nets you 9psi in stock form, or more if boost jets are fitted. When the ECU sees a signal from the DET sensor it opens a short circuit to then remove that restriction. Ending with actuator seeing true pressure and delivering wastegate pressure 7psi. 
 

So if it’s got a dead end you can check the routing. You need to plumb it correctly or the boost controller won’t work. In essence you need a feed from the piping to the boost controller and the out to a Y that goes the the actuator feed. Hopefully it’s already like this. Once deplumbed you can unplug, unbolt and chuck them. Mine are long gone. 

mine still has 2 lines in the the solenoid at the moment, the 3rd one on the y piece you mention feeds straight to the boost controller with the other joint of the 'y' capped, I've left them as they are for now as I didn't have any caps to go on the intake lines, I'll get it tidied up at some point.