How to Replace Spark Plugs 00-12 Subaru Outback

Difficulty: Intermediate · About 70 min · Subaru Outback

Replace the spark plugs, including removing the air box for passenger-side access, on a 2000-2012 Subaru Outback.

Steps

1. Open the hood to the service position

   Pull the release lever under the dash, release the safety latch, insert the prop rod, then set the hood to its service position.

2. Remove the driver's side spark plugs

   Remove the spark plug boot, loosen the plug with a 5/8-inch socket and extension, then remove it the rest of the way by hand.

3. Install the new driver's side spark plugs

   Seat the new plug in the socket, start its threads by hand, snug it with a ratchet and torque it to about 15 ft-lb if your wrench fits (otherwise just snug it), then reinstall the spark plug wire.

4. Access the passenger side spark plugs

   Remove the intake duct by prying up its push clips, loosen the clamp with a 10mm socket, disconnect the mass air flow sensor and intake hose, loosen the air box's front and bottom 10mm bolts, then remove the box.

5. Replace the passenger side spark plugs

   Remove the spark plug wires, insert the spark plug socket and remove each plug with a ratchet and extensions, insert the new plug and thread it in by hand, snug it up, then reinstall the wire — repeating for the front cylinder.

6. Reinstall the air box

   Reconnect the intake hose, reinstall and snug the air box's two bolts, reconnect the mass air flow sensor, tighten the hose clamp, then line up the intake duct and snap its clips in.

Check your vehicle’s repair manual for exact specifications and fit.