I have an 03 Sierra that Im going to put pacesetters on. Should I get the Y pipe or can I just come straight back with pipes from the headers to mufflers or bullets?

I heard that the unequal length of the exhaust gases getting out is what makes it pop. A Y pipe will make the gases come out at different speeds and create popping right? I want my truck to sound really aggressive.

 

You can come straight back into bullets or mufflers, it's just more work. If you get the Y-pipe, you can go straight into the catback exhaust, stock or otherwise (hopefully aftermarket).

 

I have heard that if you don't run an X pipe it will sound like 2 4 cylinders. I don't think so, with a stock cam maybe but when you run a nice lumpy cam they sound mean.