Glad it worked out. The reason I didn't do the universal is bc over the years I have cracked a number of insulators bc you can get too much of an angle. Probably not an issue bc of the guide tube in the valve cover though.Just wanted to thank you for your detailed directions on spark plug replacement. The only suggestion I could possibly think of the addition of another universal for the socket set.
While you're at it, might as well both sides as cheap insurance.If you had oil on the boot or on the plug then the gasket around the spark plug hole tube is bad. The valve cover will need to be changed. You get the valve cover gasket and two round donut gaskets. If it was just a little you'll still need to do it since it will only get worse over time.
Great link. I need to change mine as well. Tho I have allready bought alot of gaskets for this.While you're at it, might as well both sides as cheap insurance.
Here's instructions from RS25 (not a Forester, but VERY similar).
DIY Valve Cover and Spark Plug Gasket Install - Subaru Impreza GC8 & RS Forum & Community: RS25.com
Spark plug seals 10966AA000 x4 $3.09
Valve cover gasket 13294AA053 or 13294AA070 (should be this one, but double check when you buy) x2 $10.46
Valve cover bolt seals (optional really) 13271AA071 x10 $2.53
(these are list prices.. vendors will get you them for cheaper)