I recently purchased an 05 Dodge Daytona Ram, 5.7L Hemi Magnum. About 30 miles on my way home a check engine light came on. It drove fine the 100 miles home.
Actually never have had any problems other that the light and the P404 code. Replaced the EGR valve with aftermarket valve and erased the code. 30 miles later it's back on. Researched and what I found most often is you have to use MOPAR OEM EGR valve. Shelled out the bucks for the OEM valve and installed. 30 miles later the code is back. I did check to make sure the tube from the manifold to EGR valve was clear. Just FYI, I did notice that the EGR valve I replaced originally didn't look that old, it was pretty clean. I am going to to the "disconnect battery" thing in the morning and see what happens. The truck seems to run fine and plenty of power, no stalling and smooth idle. I did replace the spark plugs, much needed. It has an K&N CAI on it as well. Any help will be greatly appreciated. Thanks
PS, I am mechanically inclined but lack in the electrical issues side. I do have a multi meter but am not sure how to use it to see if I am getting correct voltages. Should I visually be able to see the valve move? Oh ya, I was wondering what the cap covering an opening in the intake manifold right next to where the ERG tube connects is.

 

Moved to the correct section.

 

now getting P401, insufficient EGR air flow. Truck has 128k miles.

 

Supposedly, there is a differential pressure feedback sensor, that tells the PCM about airflow.... No idea if that is part of the egr valve itself, or if it is something else entirely.

 

I'll look into it

 

I read somewhere to disconnect the battery for 15 to 30 min in lieu of just cleaning the code. I did this and thought it worked. The check engine light did stay off for over a day or two and I thought it was FIXED! Low and behold, it came back on... This time though it is the P401 code, improper or low EGR flow... My gut Oa telling me that maybe the intake manifold is badly Carboned up and somewhat clogged.... A big maybe though. When I disconnected the battery and the light stayed out my fuel mileage seemed to go up substantially, lime 4 or 5 mpg anyway. The truck still seems to run fine with no problems.... I think the flow sensor is part of the EGR valve, I was wrong about something once, so I guess it could happen again. LOL. HELP..

 

No idea how the EGR system on your engine works..... Is it possible to clean the passages??

 

I have looked in the passages as far as one can see, not far. And tried some throttle body cleaner. The EGR tube was pretty much clean, no real restrictions. I think the next move is to try some SeaFoam intake manifold cleaner. I'll do the disconnect battery thing again as well after the clean. What amazed me was how much my fuel mileage increases for that short time after the battery disconnect last time, before the light came back on. I am wondering if the ECM could be causing the problem. Clearing the ECM with the battery disconnect and that temporarily seeming to fix it has me wondering.

 

That was one of the possible listed causes......