So I went to change my spark plugs and found oil on the top of one from where the spark plug well seal was leaking. Both valve covers were leaking, and I had a hell of a time trying to get the spark plug well seals out so I ended up just buying new covers they were only $50 a piece. Put the new plugs in and put the intake back on and now it's getting the po300 random misfire code. I'm gonna take the intake back off and make sure I got everything hooked up right and replace the intake seals. Do you guys think i should replace my ignition coils? Was running just fine before, but the truck does have 140k miles and autozone has a 6-pack of coils for $229.99.