ok, noob here so if I get any of this wrong, that's my excuse...

03 expy 5.4 4x4

1. have now gotten evap canister code several times
2. i get hiccups occasionally around 45/55 mph
3. TODAY: jammed on the brakes suddenly and immediately the engine started running very rough, I could tell it was missing on several cylinders, so I limp along at snail pace to parts store 1 mile down the road
4. turn the car off while getting plugs at o'reillys, get back in the car, crank it up for giggles and it runs fine...wtf???
5. get home, hook up scanner and got 4 pending codes for E F G H (0355,6,7,8)

WTH would cause ignition fail just on 1 side of the engine???

Worried now, since I have to take this truck 1500 miles end of the week, up the mountains and through the valley etc etc...

Planning on putting new plugs in there tomorrow, can't afford to change all the coil packs...

 

Welcome to the FTE.
Check all your electrical connections for that side including the injectors.

 

A loose connection or a short for the wires that feed the COPs on the driver's side of the engine.

 

The hiccup is a miss. I had a similar issue happen to me (minus the hard braking). After cooling down it ran fine but there was a burned plastic smell. Dealer fixed it by changing a COP, plugs and all insulators (I think the COP was probably precautionary). When you change your plugs change all the insulators on the COPS. That will likely cure your miss issue and prevent the problem you just experienced from happening again. In my case this is what fixed the issue and it has not recurred in the last 60k miles.