Most common culprits that cause what you are describing are:
EGR
Dirty Throttle Body
PCV

It's one or a combo of those three probably 90%+ of the time...

Not just Autozone, but most auto parts chain stores will pull a code for you for no charge...

 

didn't 2004 models have the 7/70 powertrain warranty? I don't remember, but I thought my 04 had it.

 

Throttle body was my first thought. The "key dance" will show the codes as has been mentioned. Be ready to write 'em down. I think they're gone once the list has displayed. 46KM is close to 30K miles. Have you looked at the plugs?

 

I have tried the key thing without any luck...i've heard its not available on the 04's. And I have not checked the plugs yet. I am probably going to go buy a code reader this weekend and I will see what it tells me.

 

Just a heads up for anyone else that may have this problem in the future. I had the EGR valve changed and that has solved the problem.

 

Just want to let you know I had the same exact problem. The surging when holding down on the accelerator, no throttle response etc. Mine would come and go. I took it to a dealer they said the same thing, an EGR problem (more than likely the EGR valve needed to be replaced) I replaced it with no change.I also replaced the MAP sensor.Come to find out it was the valve spring on #5 cylinder. The valve spring broke, but when it did, the piece that broke didn’t shoot out it moved still keeping the spring tension on the valve. It would act fine until it moved/vibrated loose causing no tension on the valve. 468$$$$$$ later and 16 new valve springs she runs fine. Mine is a 04 Hemi with 51,000 on it when that happened. Good luck.