So over the last couple of days I have noticed my fuel milage had gone to sh!t and my truck was running really a little rough. The power was there but there was a hesitation. So doing some research it could be because of the winter gas but I figured i'd do a tune up anyways. So I cleaned the throttle body, new air filter, new spark plugs, new thermostat and coolant flush. All in all took me about 4 hours to do everything and the truck was running like a dream afterwards. While doing the spark plugs I noticed I a possible leak on the passenger side valve cover. Curious to what everyones thoughts are...I was thinking I would clean the engine with a degreaser and see if there is a leak. If it does how hard is it to remove the head?