my commander was throwing o2 codes when I bought it. They told me it was bad o2 sensors and an exhaust leak. I took it to my mechanic he changed out a coil pack and fixed a wheel bearing. Not saying this is your case but those codes can be misleading.
Mine:2008 Grand Cherokee Overland 3.0 CRD...OME HD lift, JBA control arms, AEV Onyx Salta w/ 265/70/17 General Grabbers.
Hers:2007 3.7 Commander Graystone
2.25"RR lift, monroe 171377 struts, monroe 58646 shocks, JBA 6.7 control arms, Moto Metal MO970 w/ 265/70/17 Hercules Terra Trac ATII