Pros & cons ?
No regulations to fear in MI that I'm aware of.

Had mine off for a few weeks, haven't noticed any difference.
I thought the O2's would throw a code at least, so far not even that.

 

the only non enviromental con i can think of, is you have to find a way to stop your downstream O2 sensor from throwing a code, i just live with the light. but it sounds like you dont have that problem.

 

i have longtubes on with no cat , and no problems , no engine light, as long if you have your sensors in you will be ok

 

If it does throw a code, the sparkplug nonfowler trick works pretty well, and costs about 4 bucks.

I am contemplating gutting mine as I think it's partially clogged.

 

No cat, post O2 simulator from fastman into flowmaster 40 duals. No problems and great sound! Almost to loud, or am I gettin old?

 

One that I can think of is a difference in the exhaust smell. The only time I have gotten a CEL or MIL was when I had a heavy load on and was giving her hell going up a hill.

 

for those of you who have done it... is it even worth it to gut/remove it? Any noticeably gains?

 

I didn't notice any gains, except for the fact that I could accelerate above 45mph again.... Mine was shot, and I didn't want to pay for another one. I don't have to go through emissions crap so I don't worry about it.

 

well speaking of that, after installing headers I had to pull the exhaust a half inch to get it to line up correctly for some strange reason. Right after that my cat started rattling. sunday i started feeling a considerable power loss at full throttle. I knew it was a plugged cat so I hollowed it out. sounds good and has a little more power. Just threw a cel tho, I guess thats just a risk ill take.

 

PROS = better flow, deeper sound
CONS = none

I gutted mine a few months ago. No CELs and no problems.