Man, that Honda dealership ripped you off. You can buy a little scanner/reader like the one I got http://www.actron.com/product_detail.php?pid=16361 . As long as you have the OBII plug on your harness, it'll say that your smog pump isn't working (because you don't have one) etc.. but it'll tell you useful things like misfires, VTEC issues etc.. You'll have to do a google search to find the code definitions but no biggie. Plus you can erase the codes to try again. And it's good for your other cars when they say (check engine) and it ends up only being a problem with your fuel cap.
I think it's a fuel problem too...
I had a problem similar to yours, it was that my fuel line was coming loose inside the tank, near the top, as the fuel pump swang back and forth under Gs. I have foam in my tank too but that didn't stop it from swinging around. Don't know how your fuel cell is set up but if it's a honda fuel pump just sitting at the bottom of the cell with a fuel hose hooking up near the top, I'd check that it's tight at both ends. If partially off, it won't supply enough for full throttle... and it's about ready to come off all the way and leave you stranded out in the boonies. Wait that was just me, twice;) Thought I did damage to the motor the way it sounded too.
I ended up putting the fuel pump outside the tank after trying to reach into the tank to fix the loose hose and pushing/grounding the wire for the fuel pump... can you say BOOM and FLASHFIRE! There's pros & cons to having the fuel pump outside I know but I feel better now.