I've had the issue for a few years and with the colder weather it seems worse.. You recommended a fuel rail cleaning but have been unable to find one.. My local dealer has no connector for my truck. So I tried some techron and super unleaded. It actually got worse.. not sure if it was coincidence or bad gas.. But now I also have a bad lumpy idle now.. Which seems to get a little better once the engine is warm. They put a new MAF in it.. Also I have done plugs, wires, fuel filter, cleaned the Iac. But no luck. They can't figure it out.. I asked if it maybe the timing is wrong. or a coil pack is bad. or even if the injectors... It did through a couple quick misfire codes for them when they kept it overnight.. Any ideas on stuff I can do myself?