Couple of questions about new exhaust

[monkey]

I've just fitted a brand new original exhaust to my bike for a low sound level at a trackday. When I first fired it up ithe bike didn't want to run correctly. I believe the 'tune' in the ECU is ok for use with the can. After half a minute running and starting it up later it seemed ok. What could that have been? There were a few little bits of what I assume was packing coming out the pipe. Is there anything I need to pay particular attention to regarding care for the can? It actually sounds lovely for a standard can.
:)

[johnnyrod]

I though the stock ones had a solid baffle not packing? If it's running fine I would be happy. If they're not packed then they're basically maintenance-free.

[Dangerous Dave]

If its running ok now then there is nothing to worry about.

There is baffling in the OEM exhaust, even in the main link pipe that you cut when you fit a slip-on.