So, Finally had a chance to piddle with the Disco on Monday. Cleared all the codes and the only one that remains is the Service Engine Light for the 02 sensors. Put in an order for all 4 to be here next week.
Transmission shift mode lights are intermittent and when on, the transmission hangs in high gear. I plan to remove the XYZ switch and check for corrosion.
Engine runs surprisingly well and what I thought was and exhaust leak turned out to be a loose spark plug on the rear left cylinder. Luckily the threads weren't damaged and the tick, tick tick is now reduced to the other tick, which I believe is a bad lifter or two.
I did notice coolant dripping off the transmission so I'm hoping its from the throttle plate heater hose leak running down the valve cover to the back of the engine, and not an external head gasket leak. New coolant hose kit is in-route to stop the water leaks, and a transmission service kit as well.
small victories!!!