Update on this topic. I have replaced the Canister shut off valve as
suggested by rufovillo... I have reset the check engine light. It is
been a couple of days, the light has not yet come back. I have driven
the vehicle atleast 5~6 times for atleast a distance of 80 miles. I am
not sure what Honda manual means when it says that "the light will come
on when the sensor detects the problem in three consecutive drive
cycles" I am not sure what a drive cycle is, but atleast I have driven
the car 5 times, if that counts then the problem has been resolved.

BTW, if anyone is following this thread, to remove the canister shut
off valve, we need to remove the canister itself as specified in the
earlier posts by others. One thing to add is, there is only one bolt
that holds the canister to the frame. I had by mistake tried to remove
the frame itself which has three bolts. Once the canister is out,
replacing the vavle is easy, except that the two philips screws that
hold the valve to the canister are very tight ( I wonder why Honda does
not have a bolt instead of the screws !!! ) In my experience, when I
try to remove the screws, the threads on the screw almost always get
ripped off, I wonder why they don't have bolts instead !!

-- John