Loose catalyst in converter on 2000 Audi A6 Quattro

While working on the automatic transmission, the catalytic converters were removed. The converters rattled when shaken and some of the catalyst fell out the pipe. What would be the effect on the car if the loose catalyst was removed and the converters reinstalled?

Asked by for the 2000 Audi A6 Quattro
Increased exhaust emissions and it will probably keep turning on your "check engine" light and setting codes in the computer. Not to mention you will not pass an emissions inspection if your state required one.
I am most concerned about engine damage or lose of performance. The cost is prohibitive to replace the cats. I've heard of dummy O2 sensors that provide the right signal to the computer to avoid the check engine light. There is no emmission inspection here. It's common for folks here, to gut their catalytic converters or remove them.