i have a 01 gtp running all stock parts except for cold air intake, msd wires, new ngk plugs, magnaflow muffler with resonator delete and u-bend delete.. looking for a good down pipe to add but needs to have a cat. cause emission in texas suck... any suggestions would be help full and any ideas to increase hp power and torque. thanks
was told buy a muffler shop to buy a performance down pipe and keep stock cat but not sure if thats a good idea or not. please help me out.