Here are my symptons, gear heads please help...

i had a s10 with a 4.3 and it sounds almost exactly like what your describing was happening to me.. after swapping out a bunch of parts chasing the problem it turned out that my fuel pump was going bad. after replacing it the truck ran like it was brand new. just a thought?

sounds like a fuel related issue check your plugs and replace fuel filter. but check your fuel pressue also. that would be some good places to start

Would any of these issues cause my charcoal canister to fill up wiht gas like it did yesterday?

to much vacume over filling the tank clogged or kinked vent hose

im not not sure if the cel bulb puts a chevy in open loop or not my bad

prolly have an exhaust leak causing the backfiring........

does it still have catalytic converters?

I would put a timming light on it, you mat have a tooth on the timing gear broke????

my nissan will back fire every once in awhile declerating.. but b/c i have the cat, then about a foot of pipe and the stock resonator and that is it.. so since you'r bagged, your exhuast might be cut so far back its backfiring.

It only backfires when it was cutting out... the rest of the time its fine..

I put new plug wires on it, cleaned the plus, checked all my lines, checked the fuel filter and fuel pressure.. put a bottle of injector cleaner in it and filled the tank with 91..

We will see if I blow myself up.