So I was driving to work early last week, think it was Monday, and the check engine light came on for the first time as I pulled into work, hooked it up to the diagnostic scanner and it showed P0441 EVAP Incorrect Purge Flow. Was going to run a KOER test but didn't have the time as cars started coming in so I cleared the code and parked it. Drove it the rest of the week with no CEL and Sunday I checked pending codes and it showed P0441 so since it was only $25 I replaced the canister purge valve that day since that was the "most common" fix around the web. I hate throwing parts at stuff but it's been a crazy last couple weeks and haven't had time to truly diagnose anything. But at the exact same spot on the road that the CEL came on last week it just came on again today. So as usual the parts throwing technique didn't work. Lol.
Anyways I've checked all the vacuum lines under the hood, some have apparently been rubbing against the engine and wheel wells but none are rubbed through and I've tied them up. I have some dry rotted fittings on the intake that I'm going to replace this afternoon but spraying them, or the vacuum lines, with starting fluid does nothing and I hear no intake leak hissing. So I'm now assuming it's somewhere in the EVAP system itself sadly. But I've never dug much into an EVAP system. Can anyone give me some pointers on where to start with this? This Jeep got it's first serious mudding adventure maybe a month ago, and got 5+ feet of airtime from a hidden ditch on it's stock suspension, so it really got shook up but no damage, and I have a bad habit of "topping off" the tank one extra click at the gas station. If those could be of any help. Other than that, it's a very routine Jeep, as you can tell by the CEL coming on at the same spot as last time.
EDIT: For about a week before the first CEL my mpg steadily dropped from 17-18 average to 14-15, after replacing the canister purge valve it's at 16-17.