I ran seafoam through the BB line, crankcase and gas and right after i got a check engine light and ATTS light. The car feels fine ive goin through over a tank of gas since then almost 200 miles (not easy miles). I tried pulling the fuse for the ecu and also just unhookin the battery. Still no luck with gettin the lights off. I put the rights amount of seafoam in the right places and everything feels good, actually alittle better than before. Any ideas why the lights are still on? U think i killed my o2 sensor or that theres still carbon diposits coming out of the exhaust ? Any info would help cause its real annoying looking down and seeing those 2 lights.

 

Should try jumping the ECU to see what code its throwing, or just go to Auto Zone and they will check it for you for free

 

Ran into this problem myself last year. Check your gas cap. Actually my gas cap seemed ok for the most part too. I ended up taking the car in and paid the horribly high diagnostic fee. I should have known something was up since about a week or two before, the gas cap would seem somewhat loose when filling the tank (although it always went on tight).

What was happening is the fuel system wasn't pressurizing since air was being let in thru the gas cap seal. The car pops the Check Engine line because of this. Then the ATTS light lights up about 3 or 4 seconds later because the car computer locks out all other communication. So the ATTS can't talk to the computer so its light comes on. I think the gas cap was about $14 at the honda dealer.

I'd be willing to bet this is your situation!

Good luck!