i have a sido super 40 flowmaster cat back and i am looking to put in some high flow cats from magnaflow. i was wondering how to go about this without always throwing codes and having the check engine light on. and if i do throw these in will the drone be to loud or what, and will it help gas mileage. i was wondering if the magnaflow was the right way to go on the cats and if that little flowmaster could handle the extra air pushing through. and how do you think it will sound, the magnaflow going to a flowmaster?

 

This is what I want to do too.