If it were a flame sensing issue I would expect a lockout AND nothing running. The fact your inducer is running is not expected on a normal lack of flame lockout.
Since it's intermittent it will be a PITA to diagnose. Here's a description of how your control should - *.*/wrdhom/pdfs/instruction_sheets/0037-4836.pdf
It seems the lockout will vary in length which implies that, after so many minutes, it will try to relight again. So I would suspect when you hear the inducer, it's trying to light the furnace. If you can, observe what happens when you're there. Does the ignitor glow bright red to white? Can you hear the gas valve opening? If you're uncertain how this should look and sound, turn off the furnace and then when you turn it back on, watch as it lights. It is possible you have a flame sensing problem albeit a very intermittent one. You may also have an inducer pressure issue so check the flue to be sure it's clear.