Im running 5" bullydog w/bd high flow muffler(no cat)i like the free flow sound&feel,but was wondering if we could quiet it down a little ,if possible?w/o of course putting back on the cat. Its real loud outside the truck(i live in &around boston. . Its REAL LOUD in the city)i've heard of a resenator but dont know what it really doesMy truck has 18000 mi(est. )and i got 21mpg on highway on short trip(40 mi @65mph, up from 16. 5mpg w/cat)again is there any thing we can do? thank all for time&response---LA