Did the BUMP kick something up that dented or crushed part of your exhaust system? Hit the Catalytic Converter hard enough to fracture the monolithic catalytic material? Send rust flakes into the Muffler where maybe it couldn't get out? Or if your Tailpipe has a Screen across the outlet?
Not about Catalyst - Fords (at least used to) have a monolith. Picture a full box of soda straws. Even better, those little hollow coffee stirrers. When the box is full, all of those little passages line up, and air (exhaust in a catalyst) can easily flow through. The exposed surface of the monolith works chemical wonders on the dirty exhaust and it come out politically correct. But break the catalyst into chunks. Small pieces will escape and possibly clog something else. But large pieces can get crosswise to the outlet. Now the exhaust is trying to get past what might as well be cracked stone in there at random.
If exhaust IS blocked, engine will produce LESS power with MORE throttle. Kick it down into passing gear and it'll rev up but the coach will slow down.
