Open the hood. Remove the two bolts that hold the stock air box to the left side (as you are looking at the engine) of the engine bay.
Loosen the hose clamp that holds the turbo inlet pipe to the air box and disconnect the pipe from the box. Unplug the wiring harness that plugs into the air box and set the wires out of the way.
Loosen the lug nuts on the passenger's side front wheel. Lift the car with a floor jack and lower it securely onto a jack stand. Finish removing the lug nuts and the wheel then set them out of the way.
Remove the screws that hold the fender line in place then remove the fender liner. Remove the lining on the bottom of the engine on the passenger's side as well. Remove the plastic intake ducting that delivers air to the stock air box. The cold air intake filter and piping will install in place of the ducting.
Install the filter on the end of the intake pipe with the supplied hardware with the cold air intake. Install the intake pipe from the fender well through the hole that the old intake tubing was installed in. Bolt the intake piping onto the engine bay. This procedure will vary depending on the brand of intake you are installing.
Install the rubber sleeve onto the end of the intake pipe in the engine with the supplied hose clamp. Install the intermediate pipe that goes to the intake of the engine on the other side of the rubber sleeve. Tighten all of the hose clamps. Plug the wiring harness disconnected from the stock air box into the cold air intake.
Reinstall the lining on the bottom of the engine and the fender liner so that the intake filter is protected from water and dirt. Remount the wheel and lower the car to the ground with the jack. Start the engine and make sure there are no leaks in the intake system.The Subaru WRX is an impressive-performing, turbocharged, all-wheel drive car available as a sedan or a wagon. In stock form, the WRX uses a restrictive air box to deliver air to the engine. Replacing the air box with a cold air intake increases horsepower and throttle response thanks to the larger piping and air filter. JDM stands for Japanese Domestic Market and refers to any cold air intake that is typically sold only in Japan.