The codes seem to be all O2 sensor circuit related.

The common wires between the upstream and downstream O2s are the grounds for the heater circuit and the ground for the sensor circuit and also the O2 heater power feed wire.

The first thing to check are ALL of the fuses in the underhood fuse block. The power feed for the heater may have an open fuse. If the fuse is burnt, check the wiring harnesses, especially on top of the trans , for chafing which may have caused the short. A internally shorted heater circuit in one of the sensors could also cause the fuse to blow.

A ohm meter across the two white wires in each sensor should show around 4-6 ohms resistance. Less than that can blow a fuse (shorted). An infinite reading will mean a burnt out, open, heater circuit. Replace the sensor/s if they are out of range.

Next, the ground for the heater circuit is at the stud on the right rear of the block where the dipstick tube support bolts to the block. It's very common for the wires to break out of the terminal. I'm almost willing to bet a cold one that this is the actual problem, it's that common! <img src="/forums/images/graemlins/cheers.gif" alt="" />

Lastly, the black with light blue trace wires to the sensors are the sensor grounds. They should be checked for continuity to ground, too. Most of the other engine sensors are connected to the same ground source, which actually comes through the PCM. It's unlikely this is the problem, as there are no other sensor codes. If it is, the open would probably be between the O2 sensor and the splice to the other sensors. You can hard wire the ground temporarily to see if the sensors wake up. If so, then trace out the circuit to find the open and repair it. The PCM filters the ground signal to keep out stray voltage which could really effect the O2 sensor signal.

Get ahold of a wiring diagram for your XJ, it will help with tracing the wires.

Hope this helps!