what will give me more louder sound and better performance? I would assume a test pipe would... but then I have to go worry about stations checking it, even tough last time, they didn't sniff my tail pipe.

Also, Im starting to think my current cat is either a little clogged or just causing my y-pipe to make that wind tunnel sound a little more rough. I know that the new flex pipe is gonna make that sound, but someone told me that If I put on a highflow cat, not only will that sound go away, but my magna-quiet will be louder. lol

 

Your factory cat is a hi-flow. Your not benefiting from a test pipe. All your doing is polluting the air more becasue there is nothing to filter.

If your cat was going bad it would stink.

 

me personally I like highflow cats. I will eat the .4 hp that I will lose over a test pipe. I have friends with catless cars every stop you can smell the exhaust and theres a buzzing noise that the cat takes away. Same level of loud with a highflow cat just less buzzing.

 

btw, Cats don't filter the exhaust. They change the gases with a chemical reaction within the coating of the cat. The honey comb portion is just the "filter" i guess. Also, I kinda doubt these are high flow from the factory. why would they make the stock ypipe so restrictive for?