I didn't drive mine long enough before I bought it for the CEL to come on. I've tested every check valve in the fuel/evap system and they all work. I'm thinking it's the gasket on the gas tank where the fuel suction tube is. The low pressure hose that goes to the fuel suction tube ruptured last year. I've got a temp fix on that, because you can't buy the hose separate from the suction tube assembly. But the fuel gauge now goes bonkers when less than half a tank of gas. I'll be dropping the tank soon and replacing the suction tube, gasket and fuel sending unit. Hopefully that will at least fix my uncertain fuel reading, if not the evap codes as well.
Sounds like you're on the right track. I replaced the fuel suction unit and gasket to try and fix the same fuel gauge problem. There was a TSB about this for 99-00 (TSB EL010-00). It turned out to be a burnt out component on the back of the cluster board I was able to repair for $10, the dealer wanted $500 for a new cluster and re-programming the odo chip.
Yeah you have to drop the fuel tank because the access hole under the rear seat is too small. It's wasn't terribly fun, I had problems reconnecting the electrical connectors above the tank. I remember having to cut one of the hoses during the job for some reason, possibly the one you're talking about and replaced with similar size fuel hose from Napa. Might as well replace the fuel pump and whatever else while you're doing it. I assume you tried replacing the gas cap?