How do you change the spark plugs on a 1991 Subaru Legacy LS?

Answer 1

since the engine cylinders are horizontally placed, the spark plugs are also in a horizontal position. the best way to find where the spark plug is located you follow the plug wire. start from the coil and follow that one wire and you will see that it is hooked on to somthingat the other end, and that is where the spark plug is. to change it you will have to pull the wire so that the plug is visible or touchable. you will need one of the two special spark plug sockets depending on the size of your spark plug, an extension rod and a rachet. if it is 4 cylinder then there should be 2 plugs on both sides giving a total of 4. i hope this helps :D

AnswerSpark plugs on the Legacy EJ22 engine are mounted at approx 45 degree angle, faced up towards you, 2 plugs on each side. Work only on a COLD engine-- not started for 8 hours or more. Stand beside the right (passenger) tire, and follow the plug wires down from the coil. Find the big red rubber boot, remove by pulling out and up, remove spark plug using a 5/8 inch spark plug socket and an extension, replace with new plug (use anti-sieze on the threads), tighten until gasket begins compressing (resistance to turning), tighten approx 1/3 turn more, remove socket, re-install red rubber boot until you feel it "click". Do the other plugs, and done. Note-- the left side looks impossible, but the extension does indeed go straight down to the plug without trouble. The challenging part is removing the red rubber boots on the left side without breaking plastic things-- try reaching in from the back of the engine. Note-- avoid standard Autolite spark plugs, they tend to mis-fire. Platinum Autolites seem OK, as do just about everybody else's plugs. Verify spark plug gap before installing.

I find that removing the windshield washer reservoir (two screws) lifting and placing it to one side permits much easier access to the spark plugs on the left hand (driver side)