still have a whistle/hum after regen valve

[mipstien]

I am better off knowing others have this noise and I'm not alone. Doesn't change that I hope to figure the problem out.

I wonder if i shouldn't just get a fully working evap system and start changing parts out and see what happens. But I also don't want to spend all that money on something that may or may not be the final cause. There aren't a lot of places for the evap system to 'go bad' without throwing codes so at least I (we?) have that going for us.