I got half way down the driveway in my truck yesterday and I wasn't liking what I felt/heard. Rough idle, sputtering under normal acceleration, and a few backfire "pops". Turned around and parked her. The plugs are fairly new and the filter was changed less than a year ago. I suspect some sort of fuel injection problem and/or fuel pump...maybe even a coil pack issue. Any suggestions?

On a side note, I know for a fact that it needs a new lower intake gasket. I'm experiencing an extremely slow coolant leak and rich exhaust smell upon startup. I've already replaced the upper intake manifold as well as IMRC bushings. When I take the plunge and replace the lower gasket, what else do you recommend I do when down there? I heard it would be the opportune time to replace the timing valve cover. Thoughts?