This means that cylinder #1 fires first, followed by cylinder #3, then cylinder #4, and finally cylinder #2.
Note: This information is based on the standard Audi A4 4-cylinder engine for the year 2000. However, there might be variations depending on the specific engine code (e.g., 1.8T, 1.6, etc.). It's always best to consult the owner's manual or a reputable repair manual for your specific model to be absolutely sure.