Is it necessary to have your cat back exhaust system welded or is it just a waste of dollars?

I've seen exhaust systems clamped together and I've seen them welded, which is better in the long run? Does it make a difference? What do the manufacturers say?
Your thoughts, opinions, and comments are appreciated.

 

Clamping is all you need.

 

As long as it's a well made kit then the clamps are sufficient, but if the kit is loose fitting or doesnt have enough overlap to clamp securely it should get welded. I've had kits in the past that only slid together maybe a 1/2 " and would vibrate apart, I decided to weld that one up after the muffler fell out when I was offroad. On my Tundra my MBRP fit together very well and has been on there for several thousand miles clamped together with no problem at all.

 

I have a borla exhaust on mine, and mine is clamped. NO issues and no leaks for what its worth been on the truck i think 3 years now. Just make sure you clean off the clamp an the connect surface if you have rust and your gold.

 

Factory is clamped.

 

So are the aftermarket TRD duals.

 

Most top of the line cat-back kits clamp on, if that tells you anything.