The Subaru Outback mixes fuel and air under pressure with a fuel injector. This function was previously performed passively by carburetors until the late 1980s. One advantage of fuel injectors is the programmable firmware that allows the fuel injector to handle different fuels. A fuel injector is comprised of only the nozzle and valve; it still requires the pump to pressurize the fuel.
Determine which fuel injector your Subaru Outback will need. This depends not only on the make and model, but also the engine size. Models made from 1995 to 1999 can have a 2.2L H4 or 2.5L H4 engine. A 2.5L H4 or 3.0L H6 engine is available on 2000 to 2004 models. Models made after 2004 are offered with a 2.5L H4, 2.5L H4 turbo or 3.0L H6 engine.
Relieve the fuel system pressure and remove the fuel cap. Disconnect the negative battery cable with a socket wrench and remove the collector cover.
Remove the air cleaner case with a socket wrench if you are removing the right side fuel injectors. Remove the battery and alternator fuel harness from the left side fuel line cover if you are removing the left side fuel injectors.
Remove the fuel line covers with a socket wrench and disconnect the electrical connector from the fuel injector. Detach the engine harness from the fuel rail and unfasten the bolt that holds the fuel rail to the intake manifold with a socket wrench. Lift up the fuel rail and remove the fuel injector from the fuel rail. Discard the old O-rings and insulators.
Install the new fuel injectors with new O-rings and insulators by reversing the removal procedure. Start the engine and check for fuel leaks.
