Since today was rainy, I decided what the heck, Ill do the "free ram air mod." I figure that it will help me on my quest for precious mpg's and give me a little SOTP power. But the real question I have is that there is a rattleing noise under the car when the car is cool, and release the clutch without giving the car alot of gas. I think It may be something in the cat rattling around. If this is the case, how can I check, and if it is broken can I just gut the cat and if I fail emissions, just buy a high flow. Will the gutted cat make the tone deeper due to more resonance, or will it give it that rice noise that I hate. Do you think seafoam will help me to pass emissions? Thanks for the imput. sorry for all the questions.

 

I just recently gutted my cat, it's loud but i like it

 

i replaced mine w/ an offroad pipe and it sounds badass. car sounds like a v8 at idle and doesn't get as ricey in the higher rpms as it did w/ the cat on. no cats + flowmaster = loud as f%ck sounds good though to me.