The 1998 Subaru Outback Legacy uses a wasted spark distributorless ignition system. The 2.5-liter engine is a flat horizontally opposed four-cylinder. A single four-terminal coil sits atop the engine. The coil fires a simultaneously spark in cylinders that are on the compression stroke and cylinders on the exhaust stroke. A common problem with these engines is valve cover leaks into the spark plug chamber in the cylinder head. This chamber will fill with oil, causing a misfire.
Instructions
- 1
Remove the two bolts in the air filter cover using a socket. Remove the air inlet pipe using a socket. Remove the windshield washer bottle bolt using a socket. Plug the hoses to keep the fluid in the reservoir. Unplug the wiring connectors.
2Remove the single bolt securing the air filter box to the body using a socket. Twist the spark plug boot to break it loose from the spark plug and pull it out. Follow it to the ignition coil mounted atop the intake manifold and twist the wire where it attaches to the coil to remove it. Do one wire at a time to prevent confusion.
3Hold up the old wire and match it for length with the new wires. Apply some silicone grease to the inside of the new spark plug boot.
4Install the new wire on the coil and spark plug. Push it on both terminals until it snaps into place. Do the same for the remaining plugs. Look for oil on the spark plug boots indicating a leaking valve cover seal. Replace the valve cover gasket and all the seals if oil is detected.
5Install the air cleaner base. Install the wire connectors and hoses on the windshield wiper reservoir and mount the reservoir on the fender. Install the air duct pipe onto the throttle body. Install the air filter and cap.
