Join Date: Sep 2006
I have no idea whether a small leak from the rear rocker cover gasket is normal or not, but mine's doing the same. I haven't been bothered to change it since the leak is very small, a drop a week or so.
Fairly easy to change yourself, you might want to use a torque wrench when putting the rocker covers back on to reduce risk of them leaking again. Considering how cheap new gaskets are, don't mess around with reusing the old gasket if it's already leaking as they can leak in spite of looking fine. While you're at it, you can change the spark plug gaskets too, at least over here they are often sold together with rockercover gaskets as a set.
Can't see how fixing a weeping rocker cover gasket would affect misfiring though.