You have a tank vent system issue. Check your fuel cap and evap lines/purge solenoid.

 

Can you share more about this fuel vent issue. What does the evap purge solenoid do and how does that affect a misfire ? Thanks

 

the tank has 3 vents, only 2 of which matter for this scenario and the last one being the tank filler neck vent for the cap and gas pump stop. one is out through the fuel pump, through the Emissions carbon canister and out to the evap purge solenoid in the rear, another line from that box goes to the front where it purges gas vapours into the intake plenum burning them in the engine, and another comes off the rollover vent valve and back to that emissions canister mentioned earlier. this is to my best memory which isnt great to begin with