ok, another update, but with a little more info. I've noticed the check engine light flicker on a couple times recently when driving. The last two codes it threw were for the egr system and the left side knock sensor. I'll check tomorrow to see if any new codes are present. Another thing, lately I've started checking my fuel mileage (which I should have been doing a while ago
). I don't have a solid figure yet, but it seems my mpg is really crappy. I doubt a knock sensor would cause this (it would only retard the timing, correct?) but maybe the egr system? I'll post as soon as I can check the codes again and fill up the tank. Thanks for any help.