2009 Impreza base evap issue

[ianmac027]

Hey guys first time posting and i need help semi urgently. So this is about my gf’s inpreza. She has a 2009 base model with 211k on the body and 137k on the engine. She has been having a recurring problem with an evap code p0457, which is a evap leak filter cap code. She has gone through like 3 caps and ive cleared the codes but it just comes back. She is on a road trip rn on the other side of the US, i was able to be with her for about a week of her 3 week trip. When she gets gas the car sometimes doesn’t start, ignition goes but never fires, she has to wait a few mins then it goes. I figure its a blockage, cut, or something in a line somewhere but a solution I had that worked for a week straight was to hold open the flap that leads into the tank open with my finger for like 15-20 secs, and the car would start right up. Stupid ik but damn if felt like it was working. Now she is driving home (8-12 hrs a day) and just called me in a panic cause she was filling from half to full and the pump keeps automatically stopping after only about a couple gallons of gas. Car wouldn’t fire had her do the finger thing for 30 secs and wait a min car fired but idled low even with ac on. She also smells gas when she has the ac on? Told her keep the window ajar. This has apparently been going on for a couple months. She has very little tools on hand and very basic mechanical knowledge. I know a bit but not about her car (I drive a 2010 corolla). Any ideas for simple fixes to get her home? Any additives or anything? I got like 5hrs until she will want to get gas again im at work rn so have limited time to look up solutions thought this would be a good first bet to ask here. Thanks for the help fellas.

 

[aoesub45]

Not sure, but I think its your canister, drain valve or purge valve. I suspect maybe the canister is oversaturated given you have issues on startup after fillup? There are some youtube videos by CarsNToys that teach you how to diagnose whether those parts are bad. Better than spending $200-$400 on the wrong part, so diagnose and hopefully its clear if one of those are bad.

If you can't diagnose it remotely, and spending some $$$ for a potential immediate fix is important, buy and replace the canister, probably get an aftermarket on RockAuto. I don't know 100% if its the canister but that seems to be the issue given opening the tank allows fumes to enter? It could be the drain valve too...they are both next to each other in the trunk, just need to remove the carpets and some foam.