So I just swapped in an 02 ej25 into my buddies forester and can not for the life of me figure out where these go. Car starts and drives btw

 

 

 

Intake is the original 99 intake so there aren't any new wires or connectors

did you check codes? Have you tested air conditioning heat and all those things?

Grey one is the front o2 sensor.

White one looks like the ECT sensor. Sensor is in the coolant pipe on top of the block. Look down just in front of the PCV hose that comes out of the block.

And if you check codes (A $10 harbor freight code reader will do) and those are the correct plugs it will be throwing codes for both of them.  

You rule!!!!