i have a 1989 civic mfpi swap that i’m chasing down dying a idle after putting in neutral to slow down issue and have some questions. i’m wanting to check the pcv valve and have a hose that goes from intake to the blue pcv valve (pictured) then into the black box on the back passenger side of the motor. it sounds fine when i shake it but i also have these 2 other plugs threaded straight into my engine block. from what i see the one with only one wire going to it is the pcv and if it is why would i have 2? also wondering what the other thing is. any help is appreciated

 

The one wire connector goes to the oil pressure switch.

The two wires go to the coolant temperature switch, which is for the cooling fan. The bullet connector with the Yel/Grn wire needs to be connected back on the coolant temp switch terminal.