$200,000 of counterfeit auto parts were recently confiscated after arriving in Philadelphia from China. Another good reason to be careful with aftermarket parts.
Counterfeit parts could be aftermarket or OEM. I’ve seen/heard of more OEM counterfeit parts then aftermarket parts.
Not just aftermarket. Several years ago there was a rash of counterfeit AC Delco spark plugs. I encountered a few misfires caused by them.
There’s more money to be made on fake OEM parts than aftermarket ones. If you’re going to print counterfeit money, would you make $5 bills or $50 bills?
There is some logic to the reverse… No one will bother to check a $5 bill so they can easily be passed and unlikely to be detected early while that $50 might garner more attention before going into the till.
Same with fake parts. You won’t get too hardcore if a $5 sparkplug misfires but you would raise a stink if a $100 coil fails instantly.
AC Delco was one of the OEM parts I knew about. Toyota is also highly counterfeited.
Not sure where AC Delco spark plugs come from these days. The division that made them doesn’t exist anymore. They may have been part of the sale to Borg Warner.