What are the two little modules that sit behind the airbox on a 95 impreza? They seem to have electrical connectors and vacuum lines going to them? one is black and one has a reddish plug?

Hi, hm, if it's the spot I'm thinking of, it's probably the AT dropping resistor, pressure sources switching solenoid and possibly barometric pressure sensor.

yeah they are where the dropping resistor was on my 1st gen legacy, but these look like they are dedicated to vacuum controls, just curious what they did or what would happen if i bypassed them etc.

Hm ok well it's probably the later two then, I think it plays some games to sense baro pressure or EGR backpressure (if EGR equipped).

oops

MAP sensor and the pressure sources switching solenoid. The solenoid allows either engine vacuum or atmospheric pressure to the MAP sensor. You'll get codes for them if you bypass them, and may get poor driveability. Best to leave them alone. If the vacuum hoses are damaged, cut, etc. replace the hoses.

Good to know. These are in the LH side of the this pic(from a 96 Lego OB but the same one used for a 98 Imp too):

The Impreza doesn't have the part labeled "pressure regulator". This is likely due to the differences in cruise control systems.

That's the fuel pressure regulator. All cars have that. Not related to cruise control in any way.

Sorry. The car left for college mid-September, was enough for the old me to forget.