It is unbelievable that the engine computer actually measures crankshaft acceleration after each cylinder fires. But as Steve postulated earlier, which happened to be correct: The "pre" catalytic converter broke apart and clogged the main catalytic converter. The debris was enough to create substantial back pressure and the engine's computer saw all 4 cylinders on the right bank (of my car not the Seine) as not firing because the back pressure prevented the crankshaft from accelerating after each cylinder fired. This must have caused the computer to shut down all of those right bank cylinders. I guess this is done to save working cats from raw gas being thrown down the exhaust pipe and burning up a working catalytic converter. Federal law states that malfunctioning catalytic converters are a warranty replacement item for 8 years or 80,000 miles. Anyway I have 82k on the car so I Know the part is not cheap. There are no aftermarket makers yet. In my case my 1999 E430 will not have aftermarket products available for another 3 years or so. I did allot of research and I found a few aftermarket universal converts that could possibly have been welded in place. However almost everyone in the know said I could wind-up with an equally crummy running engine because the computer is not seeing the precise changes it expects to see before and after the first converter. This time I did not have the time or will to experiment, especially since if I had to go O.E.M. it was going to cost $900+ AFTER all of my experimenting. I hope this helps someone else out.
-Lou