Welcome aboard! Lots of things that need attention first, as Pap says, timing belt is number one if it has not been done. Next is get the CCV out of the intake pipe and do the EH mode, your engine will thank you for it. If you don't have to withstand emission inspections in your area, disable and plug the EGR valve off, do so ASAP. If you have to withstand emission tests, unplug the MAF sensor to disable the EGR between tests.
Other items to consider: Remove the CAT and replace with a straight piece of pipe and replace muffler with a free flowing muffler like a Flowmaster. There are instructions on this site on the hows to do all of the above. If you got questions, just ask, you will get answers...
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Supporting Vendor and Moderator of LOST05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount98 Dodge Cummins 24 Valve