According the jeep manual the 4.0 with federal emissions package has one sensor before and 1 sensor after the cat. That is strange, because the fault code you had was stating 2/1, which would led believe you should have 4 O2 sensors and the California Emissions package.
JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.