If I take the mufflers and resonator off and put a pipe in their place will it be safe, Pat did it to his Aurora and says it gives atleast 15hp and wont really hurt the car. If anyone has any information about this I would be happy to hear it.

Yes, I took off resonator and took off old cat and put a high flow cat with 2 1/2" pipe back to mufflers and put two flowmaster delta flow 40's on. Sounds great and haven't had any problems.

Yes, I took off resonator and took off old cat and put a high flow cat with 2 1/2" pipe back to mufflers and put two flowmaster delta flow 40's on. Sounds great and haven't had any problems.

How much did it help performance by switching cats and mufflers? Do have E-check in your state and did it pass? Is it too loud?