2006 Ram with engine light frequently on. Trouble code p0404 EGR valve. I have replaced the coils, plugs, 2 o2 sensors with mopar sensors, EGR tube and Valve (twice). Truck is sluggish shifting gears, sometimes runs great, sometimes stalls. this battle has been going on for 3 months and the truck is winning. Each repair has resulted in a slight overall improvement but I still get the p0404 code. When I clear it, it stays off for a few days then on again, particularly if highway driving. Anyone have a similar experience or clue as to what to do next?

 

I've been having similar issues with my 06. Not stalling but the lack of power and miss firing. Done the same repairs as you and still no resolve. I'm going to try changing the fuel filter and see if that helps me out. Thinking mine is partially clogged because my light only comes on and flashed miss fire code when I'm accelerating and goes away at idle. Might be worth trying in your case too.

 

How is the EGR valve controlled on your trucks? Is it part of the EGR valve itself? Or is there a separate solenoid that provides vacuum to it?

 

Not 100% sure. Has a wire harness plus the line going from the egr to the intake manifold. Not sure if there are any other parts that control it

 

Check/verify that it actually have a viable vacuum source.

 

So after my last post I ended up changing my spark plug coils again with better quality ones, checked all wires I could see and reach, and all vaccum lines, filled up my tank with higher quality gas and booster and injector cleaner. Took the truck on a long drive(2hours) was running a chance of really messing something up but after replacing all that I did trying to solve the issue with rough running and misfire I felt ok doing it. After 1 1/2 into the drive my engine light settled down and stopped flashing. I reset the pcm the next morning and reset the codes. Been a few days since and a few hundred miles and so far no light and truck is running great. I'm thinking I got gas with too much alcohol or water. My truck did need the tune up as well(160k) but no cel and my milage is back up. Will post again in about a week if no problem arises detailing what I went through and checked.

 

I was wondering about the cleaner. Tried seafoam twice and each time I would get the misfire codes as well as egr. I will try the better quality gas, that makes sense,