I noticed the service light and check the codes and found a p0404 and p1404. Been easy on the car lately so I stood on the throttle and found good acceleration but once you get to 30 MPH + the car make a loud amount of noise from the exhaust and stutters and looses power.

Letting off the gas and it cruises ok.

Took off the EGR valve and cleaned it and found no issues. Trying to start the car with the valve off was not possible as it would not idle at all.

The car idles fine. It is just when you wind it up it will start to take off but then looses power and makes a bunch of noise.

Try this with a diagnostic scanner...
Disconnect EGR electrical connector.
Connect scanner
Turn power on, but not running.
Clear the code, then immediately turn power off. Remove scanner.
Reconnect EGR electrical connector and restart car.

After I cleaned the EGR valve the code is no longer there. I'm sure it will come back again as the loosing power issue under heavy accelaration is still an issue.

sounds like your valve is sticking.

Symptoms

There may be no symptoms of a P0404 DTC other than the MIL (malfunction indicator lamp) or check engine light. However, Exhaust Gas Recirculation systems are inherently problematic due to carbon buildup in the intake manifold, etc. This normal buildup can lodge in an EGR valve, holding it open when it should be closed. If this is the case, the engine may idle rough, or not at all. If the valve has failed and is NOT opening, then symptoms would be higher combustion temps and as a result, higher Nox emissions. But the latter symptoms aren't going to be noticeable to a driver.


Causes

Usually this code points to either carbon buildup or a bad EGR valve. However that doesn't rule out the following:

Open or short in the 5 Volt reference circuit
Open or short in the ground circuit
Open or short in the PCM controlled voltage circuit
Bad PCM (less likely)

I'm starting to think this may be two issues. Since the code has went away after I cleaned the EGR I'm going to focus more on the missing at heavy throttle. I did notice a cloud of brown come out the first time I stepped hard on the peddle when it started missing badly. Also, searching for vacuum leaks I might have damaged a plug wire so I'm going to replace the plug wires next (probably overdue anyway since I've only replaced two wires since when I bought it in 2000). Otherwise could this be a plugged cat?

Replacing the plug wires did not help. However, the codes have not came back either. When the car is cold it seems to run better then when it warms up. The warmer it gets the less I need to push the peddle down to get it to stutter and miss. Still idles fine.

I'm back to thinking there is some issue related to the original codes p0401 and p1401 and recirculation of exhaust gas.


Any other ideas?