Loose manifold pipe on a 62...

[getto]

I was trying to remove the outermost cat yesterday and noticed that the pipe going to the engine was loose. Could this account for my poor gas mileage and lacking power. I had originally thought that my cats were clogged but the PO had popped through them already. Which brings me to my next question-when I am climbing hills and putting stress on the engine I can smell a burning smell. Is this probably the loose pipe? Thanks for humoring my dumbass questions.
Todd

 

[Mr. Toad]

Burning smell: You probably are smelling the exhaust that's spewing out under the bonnet.

Loss of power: Probably not from an exhaust leak.