Yosh RS3 4-to-1 Full Race Duplex Exhaust - PC3 needed?

[InfiniteReality]

It was on the bike when I picked it up and just now figured out which Yosh it was.  There has never been a PC3 installed on it, but after finding out it's a race exhaust I'm assuming it's more free flowing thus I'm in need of a PC3 I think.  I know it'd help if I got one, but just want to see if 100% necessary to get one right now and charge it on the card or if I can wait. 

I'm also thinking of chopping 1/3 of the muffler off to make it a stubby exhaust.  If I don't need a PC3 now, will I definitely need one after chopping it? 

Thanks for any help!  I'm scared the engine might be a little damaged, though it runs really strong.

[yabu]

you don't need a pc3-add a k&n filter and have the shop map it--

[InfiniteReality]

Can they map the PCM without the PC3??  I thought they went hand-in-hand, but I'm not expert.   Thanks!

[mimic]

If you want the extra HP, you need a PC on it. you will gain 6-7 hp more with the PC then without and just programming the ecu with the yosh computer.

[Dolent]

Get a PC3 and add a BMC filter (or K&N) If you want longevity out of the motor get the non-race BMC