EGR, MAP Sensor, etc all effect the emissions of the vehicle and should be covered under the emissions warranty. Although Basic warranty is 3yr 36,000, I believe the federal law for emissions related components is 5year 80,000. Research it before you go spending your own money on this. If the dealer says its not covered make them show you in writing in the warranty policy where its not. They have detailed handbooks and what parts are covered and for how long.They don't always use them. Look in your Owners manual or warranty book. There is along list of items covered under the emissions warranty. Generally if the component affects operation and can cause the vehicle to pollute, its covered. My mazda battery was covered under the 4yr 48k mile bumper to bumper. Dealer said no. I showed him the Owners manual section on warranty, he looks it up in his book, I got a new battery. Make them do the home work and fix the truck.
On edit :Well after all that, its got a 5yr100k powertrain warranty.
This article says starting in 2006 all Liberty CRD (engine)gets a 5yr/100,000 mile warranty. Check it out
http://www.greencarcongress.com/2005/06/jeep_libtery_di.html FOund some other articles as well, the engine and powertrain have a 5yr 100k mile warranty. Get it fixed under warranty. Same for the guy with the bad turbo.
Unfortunately, the Jeep CRD is an Italian made diesel with lots of emissions stuff bolted on to meet US regs. They found something that would fit, instead of altering the design to use a Mercedes built diesel, trying to keep the price down.
RSTDdog