Yes, could be limited fuel supply but also reads like clogged exhaust, collapsed Cat or muffler.
It can happen suddenly, have someone rev engine while you feel the tail pipe flow, you can usually tell if flow isn't increasing with RPMs.
Injector issue wouldn't fit description.
Low fuel pressure would, you can rent or "borrow" tester from auto parts stores.
'01 should show 65psi when idling, raise RPM and see if it is dropping.
It should also hold pressure when engine is off, should stay above 50psi for a few months.
Pull out a few spark plugs and see if they can tell you anything.
Google: spark plug condition