Krack499

iTrader: (1)

Anyone know how different my 97 4.6 will sound if I remove my back cats and buy a cat back system from flowmaster Im currently just running duals with no muffler will it be louder since I'm cutting out my cats or will adding the flowmaster muffler just cancel it out

ZachStack

it wont only change your sound...it will kill your gas milage. someone cut the cats off my truck...all 4 of them...and it killed my mpgs. do not mess with the cats...if your gonna do anything take off the muffler. trust me. im looking to get cats for my truck to get some mpgs back.

ZachStack

if you want it louder...reduce your pipe diameter.

Krack499

iTrader: (1)

I already took off my muffler and it's at 2.5" pipe

ZachStack

Go even smaller on the pipes...like a 2 inch or smaller. Itll make it louder

samhunter99

When you take off your second set of cats you take off what actually makes your truck legal. The first cats preheat the exhaust fumes and the second cats actually do the conversion of the fumes into safer form. So basically if you take off your back two you're just heating your exhaust and letting out the harmful fumes, yes you probably don't care about that as much but still. Any exhaust shop will confirm what I say here. Better to just leave them on man

ZachStack

and a muffler shop wont touch your truck if you dont have cats on it or they are breaking the law and can get into some trouble.