Exhaust help
 

I just recently straight piped my 15 lancer ES with 2.5 inch piping hoping to get a better sound from it and it worked. Sounds great when I'm idling at low Rpms but when I get on the gas it sounds horrible it's like Someone took a can and started blowing a lot of air through it. Is there anyway I can change that sound without doing too much to the exhaust???