I had a 96 gt mustang and I put 2 flowmaster mufflers on it but got little sound because of the 6 cats! I now have an expedition 5.4 which has 2 cats. Will just a flowmaster give me sound?

 

My Flowmaster 40 has good throaty sound. SIDO.

 

It will sound pretty good.

 

yes it will give you sound, anything besides stock will give you sound. it will have a nice roar to it depending on the series you get, there are a million flowmaster videos on youtube go check them out and see what you think

 

I got the 40 series muffler and left everything else alone. I heard some people on here hollow out the 2 rear cats to get a little more sound? Is this easy to do and will it cause any check engine light issues?

 

Could you remove all 6 and replace them with 2 high flow cats or is that against the rules?

 

No F150 has 6 cats, the max # they ever had was 4, on 1997 - 2005 models. 2005.5 - present only have two, so you only have two converters. And as for the cat modification, that all depends on what your emissions/inspection allows.

 

i have 4 cats on my 98. my mustang 4.6 had 6, it was a 96. i dont have any emissions in VA! whoo hoo!!!!!!!!!!!!!! is it a difficult task?

 

If a shop is willing to do the work, buy cats, and run them over quickly and tell them to install them and re-mount the O2s properly.