I have a 99 civic LX sedan. 260,000 miles. Lately it's been misfiring like crazy when cold. Check engine light sometimes flashes then stays on solid once it's warmed up a bit. I have relatively new plugs and wires and a fairly new cap and rotor. I thought maybe it was the gas, but I let it just about run out and filled it up and it's the same issues. Any ideas?
I'm thinking maybe a temperature sensor, but I don't know a ton about this stuff.

Thanks!

-d