I also meant to mention that when it went into limp mode the first time while on a road trip last month, I took it by a dealer that diagnosed both the turbo and low pressure EGR cooler had failed and needed to be replaced. Turbo replacement would be covered by the 100k/5 yr powertrain warranty...
Have you made any more progress on this one? I have a similar set of codes (P049B and P0299) with the Jeep going into limp mode. I have it at a dealer to diagnose, and they think it's the low pressure EGR cooler, and they may be right, but their procedure is to remove the body to get access to...