Car ran ok, until recent deep freeze. Once it would start, I had misfire. CEL had been on, but hadn't checked it yet.
CEL now:
- P0302 Misfire Cylinder 2
- P0401 EGR Insufficient flow detected
- P0401 EGR Insufficient flow detected
- P1399 Misfire in any cylinder

Ive replaced spark plugs, and it seemed to improve, though still misfiring.

Question... Should I replace
- EGR valve?
- Check/clean EGR holes?
- Rotor cap/plug wires?

I don't mind doing all the above, but need to know what would get it running normal first

 

If I were you, I would pull the fuse to clear all the codes, put the fuse back, start it up, and see what codes get set again. The EGR code could be something old, and that system won't cause misfire. Any puddles of liquid found under the engine block once the temperature rose back up to "normal?" I ask because the freeze part of the country experienced would have required antifreeze protection that a lot of cars don't have. Check your coolant level to see what you see.

 

Nope, if the EGR valve itself was no longer functioning you would get the lift sensor code(P1491) or voltage issue code(P1498), your code is of lack of flow. This means the port(s) are most likely blocked. Valve is functional.
Yup.
If a 96/97 F22 pull the injectors/fuel rail and remove the EGR manifold, clean it and the ports to each runner. Be careful on the F22 intake, each port is a different size, cylinder #1 is about the size of a #1 flathead, while #4 is about the size of a # 2 flathead. Don't modify the port sizes, they are different for a reason. Very rarely are the ports under the EGR valve itself blocked.
If a 98-02 F23 pull the upper plenum off the lower runners, there is only a single feed port and that usually gets pretty gummed up clean the plenum, check the base for blockage.
If due or the components are worn, yes. They are always worth replacing. Only use Honda, or OEM supplier, spark plug wires. The typical generic units do not have the boot shape correct and they pop off the plug.
Verify there is no oil down the spark plug tube either. If an oil leak this will also cause a misfire.

Three normal wear items that will cause misfiring.
Worn ignition components.(most likely spark plugs are worn)
Valves in need of adjustment, check every 30K miles. Exhaust valves are always the tight ones.
EGR port(s) are clogged and require cleaning.

If the car has over 90K miles and you have no records, just do the above three as they are most likely in need of TLC.