flatblack83

I recently had my exhaust done with dual 3 inch stainless from the motor back to a set of magnaflow cats, dynomax 2 in 2 out xflo muffler and it exits at each corner. Now the magnaflow cats rattle really bad and are only about 8 months old. The muffler is real loud also after only a few hundred miles but i like the sound. The cats i need for a visual inspection here, so i ordered a set of high flow cats without heatshields. Can i add resonators, glass packs or anything else to quiet it instead of changing the muffler..? Any ideas...? The truck seems to run better with dual 3 inch coming from a single 3 inch. I am going back next week to have the cats cut out and the new ones welded in. So its a perfect time to do the rest, this place welds every seam and hanger so its all leak free.

here are the cats and the muffler i used

5 inch Diameter 100 Cpsi Cell High Flow Catalytic Converter 3" | eBay
Dynomax 17554 Ultra Flo Welded B x B Muffler Dual in Out 3" | eBay

GRRR65GTO

Well if you only need the cats for a visual why not punch out the the ones right now that are giving you issues and weld them back in? And since that would make it louder some resonators wouldnt hurt either

flatblack83

I would like the cats on the truck for the smell also, so thats why i bought a set of stainless high flow cats. I was just reading through google searches, i might add a set of magnaflow magna packs instead of resonators but at the moment i am not sure whats best to do.

Vortec350ss

iTrader: (20)

High exhaust pressure and flow on a boosted motor is hard on the cats. This is fairly common. It's a big reason why I just went catless...

terravast4

iTrader: (25)

yep.if the cats are too close to the header collector they can be easily damaged. i melted the internals of my stainless works cats. i did a custom exhaust and ended up putting them

flatblack83

Thanks guys... The sad part is these cats are about where the factory ones were, about right around the passenger door. The magnaflow cats do seem a little cheap tho. Thats a decent distance back but now they get way better flow. They were on with my single exhaust for about 8 months, it was only a few days later after the duals were run that they rattled. I did get on it alot to hear the new sound and to see if it made a differance. I would like to run it without cats but look at the rest of the truck..lol.. i'm lucky i am left alone with that much. The new cats that i did buy are high flow and for high hp, hopefully these will work. To calm the exhaust down i think ill try the 24 inch long stainless magnapacks right before the xflo muffler. The exhaust is pretty nice that they did, welding it all together was pretty nice. So i made an appointment to get the new cats and whatever else i add.

gammey4

iTrader: (4)

I've got dual 3" exhaust (no cats) with magnaflows and resonators and it's still pretty loud. I'll buy your old cats if you want to sell them, I just need them for visual inspection.

flatblack83

Ok, i had the magnaflow cats removed and there isn't much left on the inside. I could of left them on i guess but i wanted it taken care of. I bought a set of magnaflow 4 inch round mufflers 14419 and set of mandrel bend solutions high flow race cats. It was all welded up and it sounds great, its a little quieter and alot less raspy. Its the header pipes until the xmember, then the cats then the 14419s and about 4 foot of pipes until the xflo. No drone and the cabin noise is pretty calm.

Vortec350ss

iTrader: (20)

I hope they survive!

flatblack83

The new cats should, they are good for big hp. More than i will ever make, we will see i guess. The 14419s i am not sure about but i didn't see anything on them when used in higher hp loosing anything but their loudness.