I recently developed an issue with my late 96 XJ with a 4.0l. I went through some water the last time it snowed, and have been having issues with lack of power, backfiring through the intake, and stalling and dying out I have thrown every sensor I can think of at it, and it has gradually gotten worse every time. List of new sensors include; TPS, MAP, CPS, CAM/IGNITION PICKUP, ECT, Plugs, Wires, Coil, and both o2 sensors. I reset my ecm after replacing all these so I have no codes that come up. I'm chasing wires at the moment but everything looks as it should other than being a little dirty. ANY HELP OR ADVISE IS GREATLY APPRECIATED!!!

 

How deep was the water?
Did the water stall the Jeep right then?
Have you checked your O2 sensor wires for burns, breaks or tears in the insulation.
Eliminate problems with engine by doing compression test on all cylinders, Check fuel pressure at rail to be in spec. Verify that the firing order from distributor to spark plugs is correct.

 

The water wasnt deep, just a few inches of snow on the highway, I replaced both o2 sensors and the code went away, on the sensor on the cat the sensor itself was broken where the wires went into it. It's running super rich now and I'm sure flooding the engine.

 

I don't believe the rear (downstream) o2 sensor has any effect on the motor, I think.
You may have an unrelated problem from the water and snow.
You may want to clean and renew your IAC valve and clean your throttle body assembly.
You may also want to clean and renew you MAP sensor.
Also, from experience, my Jeep doesn't like other than OEM sensors, especially the crankshaft position sensor.

 

Step back from the parts cannon! Bruce is correct about the sensors. Mopar preferably, required for CPS. NTK for O2 sensors. If the sensors you put in are anything else, you might as well start putting the old ones back in asap.

You need to start testing. I second Bruce's recommendations. Compression test on the engine, fuel pressure testing. The wiring checks is a good thing to be doing, but my suspicion is that your issue has to do with either fuel (like a failing pump or pressure regulator) or CPS (assuming yours is an automatic).

I routinely drive through 2-12 inches of snow during the winter in my 95 and have never had it affect my engine running.

 

I've pushed deep snow up to the hoodline and never had a problem with it running rough or stalling. I hit a deep puddle at 40 mph and besides almost loosing control of it's direction, it only stumbled a bit until the plugs dried out. One thing I WILL tell you is a soaking wet air filter won't pass any air.

 

Not sure how new to you this 96 is, but I 3rd checking the compression and fuel pump. I also own a 96 and have went through similar issues. The 96 uses a different fuel pump assembly than ANY OTHER JEEP XJ year. Just keep that in mind.