I have a 2011 Street Glide and want to put some Vance and Hines Dual Header Pipes and slip on exhaust on it. Do I have to go with a fuel pack or power commander our can I just put the new exhaust on?

 

If you're only doing exhaust, you'll be ok. Mess withthe a/c, and you'll need more fuel.

 

If you were sticking w/stock header & adding different pipes - then it would be OK, but headers + pipes = lean to leaner motor. Get yourself a tuner & then everything's set for the next motor upgrade (air, cams, etc...). I have Dobeck TFI & it was only $150 w/veteran discount, but there are a tone of decent tuners available so time for more research.

 

Some have said that they were able to change the headers and the mufflers without messing with the tune, I wasn't.
I put on rinehart 3.5" slip ons and was fine.
I gutted the cat, put the rineharts back on and had a lot of pinging on acceleration
I gave Fuel Moto a call and got a tuner and went with a V&H pro pipe and stage 1 a/c