Muffler and Cat Delete legal in PA?

Is a Cat and Muffler Delete legal in the state of PA? i have an 87 Mercury Grand Marquis and i want to know if its legal

 

even if it's legal, decatting a car isn't worth it for how much more shit you're putting in the air.

 

i know that and I don't really care I'm a redneck that would swap a cummins 6.7 into a toyota prius

 

Have some consideration for the environment and people's ears.

 

I just want some extra cheap power.

 

removing the cat isn't going to give you much power though. remove the mufflers, and block off the EGR, sure.

 

Does install more mufflers in parallel increase horsepower without increasing noise?

 

probably not, since the gas still only has to go through one muffler, and having so much more area through the exhaust means you lose most of the scavenging effect.
if you boosted or cammed the motor, it might benefit from more exhaust area, but otherwise, having it at stock size (or maybe a little bit bigger) is best for performance.