Alright

Im racking my brain, and not sure where to go from here.

On my sedan I'm running factory manifolds with test pipes. Have custom made 2.5 in system that goes off the test pipes to a x pipe. From there it goes to two magnaflow race mufflers, basically just big *** resonators. On the back I have two magnaflow mufflers, universal ones.

My question is shortly after putting them on they started sounding hollow and extremely metallic. Essentially like trash. I am not sure what muffler I should put on the back to get a decent sound and not sound like trash

 

First I would check for any leaks in the system. Since it's essentially a make-shift system, there may be some gaps along the way.
After that, I would sell this setup and purchase a quality system to use.

 

It was all bent and welded in the shop I manage. We just put the same style muffler on another car and it sounded just as terrible as mine. So I guess my question is whats the best muffler for a catless exhaust on my car.

 

Basically, I think the only option with HFCs or test pipes is a high end, high dollar (I.e. HKS, motordyne, etc) exhaust. They've engineered their exhausts to work with HFC/catless systems. I have a custom magnaflow/res delete setup and it sounds great. I have stock cats tho. I'll bet if you put your cats back on it would sound fine. Either that or get a high end exhaust.