2001 honda odyssey has a p1399 code changed spark plugs and checked coils but still has a rough idle maybe egr valve or ports blocked with carbon

Vacuum lines. And check for residue buildup preventing throttle body from closing .

Plug wires on wrong ?
Timing belt jumped ?
Exhaust Converter blocked? They only last 12 to 14 years (maybe)
Plugs Gaped correctly?
Vacuum leaks-Evap,Exhaust,Intake,PCV !!
Egr problem?

have you checked the spark plugs if its a v6 the rear plugs may not have been changed

Please read the web page at this LINK on misfire diagnosis and testing, it is the best i have found for learning what causes a misfire. The info is copyrighted so I can't copy and paste it for you.

P1399- Manufactures control Ignition system OR Misfire

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires; the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.

I have a 2005 f150,with a 4.6 and it idles rough and when you turn on the ac it wants to die. Checked the codes and there are no codes.Any suggestions?

Perform a valve clearance inspection and adjust if necessary. Tight or sticking valves will cause a misfire or rough running concern. Note: Perform valve adjustment when the engine is stone cold. 4cyl: INT 0.26mm EXH: 0.30mm (V6 engine are hydraulic and no adjust necessary.) Also check for a sticking or stuck open EGR valve. For diagnostic purposes only: Remove the EGR valve. Place a business card over the EGR passage and bolt the EGR valve back on. This plugs the EGR ports and if the misfire goes away the EGR valve is partially stuck open and is defective.
Check for low fuel pressure. Check for low compression. Check cam timing. Check for a weak ignition coil. Also don't over look the possibility of worn or broken engine mounts which cause excessive engine movement and engine vibration. -hope this helps

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires (as mrgreenz suggests); the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.
Hope this is helpful as well.

Get your self a EGR valve it is sticking or the EGR port is blocked i can tell you how to test it you have a volt meter but i am 100% THAT WHAT IT IS
Code P1399 is a pending misfire code.
HOW TO TEST

1. Check EGR position sensor voltage on the White/Black wire at idle - look for 1.1 - 1.2 volts with the EGR valve closed. If the EGR position sensor voltage is higher than 1.2 volts, the EGR valve is stuck open.

2. Can unplug the EGR valve and apply power to the terminal on the EGR valve that the Pink wire would normally go to and ground the terminal on the EGR valve that the Black wire would normally go to and see if the engine stalls at warm idle.