I have a 99 Accord EX V/6, Auto with 113k.

I keep getting Codes 300...306, misfires but nothing else. To address the problem, I did the following:

Bleed the cooling system
New Plugs, Cap, Rotor and Wires
Removed the intake manifold and cleaned the passage on the botton
Cleaned and Checked the EGR Valve
Cleaned the throttle body
Removed the valve covers and manually adjusted the valves: only a couple were slightly out of spec.

The car starts and runs great but after if warms up the idle drops off and it sometimes kills. I turn the CEL light out but it always comes back maybe in a week.

 

Could be something in the rest of the ign system, coil, ICM, ect. I would test those to see if they are within spec.