500rpm at a hot idle is normal for the Hemi. Swap the injector and coil and plug wire from #2 cyl to #1 and see if the code follows it like mentioned above.

 

Still running my original O2s, but I swapped my EGR at 50k just a couple of months ago, like you, just for maintenance, never got a CEL. I put the old one in the box from the new one and kept it for a spare, looked perfect! Couldn't believe how good of shape it was in, especially when you read on here how many guys pop a CEL for one before 40k and they are a cruddy, gummy mess when they remove them.
Probably mine was still in such good shape because I mainly use the truck for going up to the farm and back (about 720 mile round trip) about six to eight times a year and for work around the farm/hunting/fishing while I'm there. The truck almost never gets used for around town unless I need to put something in the bed. No short trips really, which is a killer on PCV, EGR, oil, exhausts and other things on a vehicle...

 

Well, after a week at Dodge, the problem was indeed traced back to a bad injector. Initially, they did a thorough top end cleaning via the fuel intake system (dicsonnect fuel pump and run the truck on the cleaner piped directly into the injection system) but that did not fix the problem. They checked the PCM and made sure the s/w was up to date, and checked wires & harnesses, all looked good. I had already cleaned the throttle body, replaced the coil pack on cylinder #2 and all 16 plugs. Dodge wound up moving the injector and the misfire followed that injector, so it looks like the problem is fixed. They want to hold it overnight to do a cold start in the morning to double check, but are confident it is fixed. Hopefully this will also take care of the erratic idle (random from 500-800 rpms at idle).