The fuel return line does just that -- it returns excess fuel from the (underhood) fuel pressure regulator to the tank.

I'm not sure how a slight fuel leak in that line has any effect on "bogging down."

(However, if the gas tank catches on fire, I suspect it'll bog down a bit.)

You must check the obvious two things -- the fuel pump relay and the 25-amp fuse.

I've found rusted return lines on several of my cars, and repaired them using ordinary Neoprene fuel hose to splice in place of the rusted-out section. After chasing a rusted pipe for 1', 2', 3', 4', 5', and 6', I finally learned to simply replace the whole damned thing.
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Don Foster (near Cape Cod, MA)