Ok my friend told me I have no back pressure and said I am not only wasting more gas but losing horsepower also. My setup is full 2 1/2 piping no resonator with obx mufflers. He said I should get headers and remove my obx mufflers and put the oem ones back on but keep the 2 1/2 piping I have. Is this a good setup or bad?

 

you might lose 5hp or so down low, but it shouldn't make a difference. Put a resonator on if you want more back pressure.

 

put the resonator back on , you just making a lot of noise and not going any faster. Look in the black market for a different setup.

 

Can I just get the muffler shop that did my exhaust to add a resonator to it? What kind of resonator should I put on it, or are they all the same?