So here's my situation. My '01 elantra is running rough again. It
stumbles at idle and at any rpm below about 2500.
This started last December. I had the code read, and it showed a
cylinder 3 misfire. Because it was going on 120k miles anyway I
replaced the spark plugs and wires as a guess, which solved the problem
completely at the time.
Now the problem has come back. Because it worked last time (and
because it cost around $10) I replaced the spark plugs again. Yes, I
know that it's not normal to have to do so this often, I just wanted to
see if it would solve it again, and to see if something was
fouling/damaging the spark plugs. No such luck, it's say 40% better,
but still bad. So I found an autozone, had the code read, and this
time it shows a cylinder 1 misfire and a "major evap leak". The kid
then asked me if I had done any damage to my gas cap lately. No, I
didn't think to get the actual codes, but I could get the codes read
again if that would help anyone.
So my question for all of you is what part of the whole fuel vapor
capturing system (which I'm only mildly familiar with) would cause
this, and where should I look next? I'm assuming that even if the gas
cap weren't airtight that it wouldn't cause engine problems like this.