Hello All. Just wanted to post something in case anyone has a similar
problem. Recently, the engine light came on in my 2001 Honda CRV (4
cylinder, 5 speed manual). I noticed a slow drop in fuel economy,
from an average of 26.5, slowly down to around 21.5 over the course of
about 1 month and the engine began to idle harder than normal, with a
slight jump. I took it to a Honda Dealership and they told me it
coded for a misfire in cycliner 1. They said it could be spark plugs,
coils, or fuel injection. About 2 weeks later, the engine light began
flashing when I sat at idle for about 30 seconds. I immediately
called another Honda dealership and took it in. Analysis said it was
actually a misfire in all 4 cylinders. Apparently there was a tech
bulletin that this model had shown a tendancy to build up carbon on
the head gaskets and "gunk" in the valves. This lead to the misfires
and loss of fuel economy. Honda changed the spark plugs, cleaned and
adjusted the valves, and performed a top end cleaning of the gaskets.
Problem solved. Idle was back to normal, gas mileage was back to
normal. The entire job cost about $250.

I searched this group for answers when I had the problem and found
some useful information. I just wanted to help out any of you who
might have this issue in the future.

Good luck.