Ok, I'm welding up a 22'' Magnaflow resonator tonight. Does it need to go a certain way? Does it only flow one way? How do I tell?

 

I never thought there was a certain way it should go because its completely through. Now a cat goes a certain way because of the way it is made inside. But for resonator there isnt a way that i know of.

If there is you should see an arrow.

 

Yep, no arrow.

There's arrows on the box in the picture. I guess it was just for the effect of showing the use.