After talking with the local Dodge dealer and another muffler shop-I've decided not to mess with the Y-pipe.
Dodge dealer dissuaded me from changing it as did the muffler shop. Muffler man said he's done it before and the difference in flow wasn't that measurable. Plus-he said I'd be fighting a check engine light from then on out.
He also said that the catalytic converters are steel spun (???) and that they flow very well-much more so than porcelan (spelling?) so those don't need to be messed with.
For the most HP/Torque increase-he advised going with a muffler swap and cutting out the resonators.
I discussed the magnaflow catback bolt on system and he said there would be little difference in simply adding the magnaflow muffler and cutting out the resonators than their bolt on system. I told him that they advised I could expect 12-15 HP gain with their catback system and he agreed that that was feasible. I will re-confirm all of this when I go into the shop to have it done.
Further, I emailed magnaflow and they off-handedly confirmed the same-their bolt on catback system removes the resonators.
According to the muffler man there would be little difference between the two and I'd save a ton of $.
I've read several threads on here where there was no need to swap our OEM piping for magnaflow's entire bolt on kit and was thinking the same thing.
Welded up the magnaflow would be between $140-180. If I later decided to re-attach the resonators he said that'd be $40
So, I'm going to just do the muffler and remove the resonators for now. Muffler man said the 18" magnaflow wouldn't be obscene loud so I'm going to give that a go.
Last edited by MidwestJ; 09-14-2010 at 10:43 PM.