The cylinder misfire can either be a separate issue or an effect of the first. To begin with,
addressing the evap system issue is your biggest concern. This is a part of the gas tank
vapor removal system. If your tank was ever topped off, the overflow of raw gas went into
your vapor canister. If this happens enough, the retainer membrane dissolves n little
charcoal pellets get sucked up into your evap purge solenoid (this regulates how much of
a vacuum is put above your gas to suck out fuel vapors), either clogging it or trapping it
open. If it gets trapped open, your gas tank gets a vacuum above it and the fuel pump
can't overcome the vacuum created by the purge system. On the other hand, if your purge
system has leaks in it (busted or leaky vacuum lines) your ECM learns about this n sets off
it's check engine light. To check to see if the purge system is trapped open, there are 2
tests. 1) does it take a long time to fill your gas tank n does it run fine if the tank is full
getting worse as the fuel bleeds off?, and 2)remove your fuel cap n drive around n see if
the problem goes away. Don't worry about the chk engine light rite now. Your only
diagnosing at this point. Last but certainly not least, if you intend to do more repairs on
your own, invest in an engine scanner with live data capability. They run $30-50
depending...
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