backfire?

Vehicle--> 1999 GTP........I was wondering If i have my u bend deleted, and leave my stock cat on,when i put 3 inch pipes out to the back from my cat without mufflers will my car back fire?? or sound bad?

I doubt it will backfire but it will sound bad as there will be not deep tone to the exhaust. Good free flow mufflers will allow it to sound much better than open exhaust.