The Subaru Impreza WRX is powered by a turbocharged boxer motor. There are numerous reasons why you might need to remove the turbo. Maybe you need to rebuild the stock turbo with new internals, or maybe you are installing a new turbo that will allow the motor to make even more power. Whatever the reason, removal of an Impreza turbo is not that difficult.
Before beginning the turbo removal, spray penetrating oil on all of the bolts that will be removed, particularly the ones for the turbo and the downpipe.
Jack up the car and place securely on jackstands.
Using the 12-mm socket, unbolt the two bolts on each of the two intercooler brackets.
Remove the three vacuum lines that go to the pipes connected to the intercooler.
Remove the vacuum line and using a socket unbolt the bolts for the blow off valve. Next, loosen the throttle body clamp that goes to the intercooler and then the clamp on the pipe that goes from the intercooler to the turbo. Remove the intercooler by wiggling it back and forth to free it up.
Unbolt the left side intercooler bracket with a 12-mm socket.
Remove the heat shield for the turbo. This is held on with six 10-mm bolts, and some of them are not readily visible.
From underneath the car, unbolt the downpipe from the catalytic converter with a 14-mm socket.
Remove the downpipe from the turbo with a 14-mm socket. It might help to use a small extension. There are three nuts that are attached to studs and two that are attached to bolts.
Slide a pan or some type of container that can hold coolant. Remove the water lines that go to the turbo, as well as the oil feed tube with a 14-mm wrench. Make sure all vacuum lines associated with the turbo are disconnected.
Remove the three 14-mm nuts that hold the turbo itself on. Loosen the inlet pipe that goes to the turbo and the turbo clamp. There is also a 10-mm bolt that holds the oil line to the turbo that needs to be removed. To remove the turbo, wiggle it around. The oil feed line needs to be gently pushed out of the way, but be very careful not to damage it.