Or aftermarket parts which aren't very well made. When I was a kid, my dad always went to Grand Auto & Scherba's because they sold parts for less than dealership prices, and offered the lifetime warranty. A lifetime warranty on a cheap aftermarket auto part.
Auto parts stores used to offer "lifetime warranty" on all sorts of parts......water pumps, alternators, universal joints, drive shafts.........Not because O'Reilly's or Auto Zone sells superior auto parts. Their parts are terrible compared to OEM parts. Most people don't own old cars long enough for those parts to fail again, and again, to take advantage of the warranty. If you replace a water pump at 200,000 miles after 20 years, you probably won't own that car for another 5 years or drive it another 50,000 miles.
Does Pep Boys install OEM parts?