follow the bottom right hand pipe to underneath the engine remove pipe and then remove thermostat housing and replace thermostat the same way as it comes out.
Check out the related link for instructions on how to remove the back seat from a Subaru Impreza.
Subaru Impreza GT (2009) Subaru Impreza WRX Subaru Impreza WRX STI
It's inside the lower radiator hose.
I have a 2002 Subaru Impreza Outback and it have the thermostat on the right bellow the engine. You can fallow the hose from the radiator that goes to the bottom of the engine.
You may need to replace the radiator thermostat and gasket.
just underneath the front of the engine follow the right hand pipe from the radiator and you will see the thermostat housing.
Spring side goes towards engine.
Subaru Impreza was created in 1993.
A 1991 Subaru Impreza might overheat because of a leaking cooling system or because of a damaged thermostat. You might also have a damaged or leaking radiator or a cooling fan that is not working.
Take of bottom radiator hose at the engine block and unbolt the 2 10mm bolts thermostat is behind that.
Just changed this thermostat last night on a WRX (not sti). Just follow your lower rad hose (not very long) until you find the housing. Only two 10 MM bolts to remove.