Ok, first off, i'm a long time visitor of this forum, new as a member. love it, have gotten lots of great info and help from it. I followed this thread and found that link to the dynomax exhaust. I already had installed the mbrp exhaust from the large resinator and back to a single exit. sounded ok, but wanted more. Didn't want to buy the complete dynomax system so called them to find out if I could just get the y pipe to eliminate the LARGE resinator. answer was yes and any auto parts store that carries walker or dynomax exhaust will have it or get it quick. So I got it, installed it with a reducer from 4" to the 3" going into the mbrp muffler. sounds AWESOME!!!!!! have had it on for about a month now, but here is the problem I am finding......I've lost 2 miles per gallon and have noticed a significant loss of power!! I'm going to assume its due to a lack of back pressure? too free flowing for a gas engine?? any thoughts on this?

Thanks,
Gary