a WARNING about ebay aftermarket MAF sensors

[ppbon]

... and not all MAFs sold as aftermarket are reconditioned.
A couple of years ago I had the chance to speak to one of the factory's engineers and we started talking about Mass Airflow Sensors.
I asked him why the OEMs sold by the dealer were 2 or 3 times as expensive as the new Bosch (with the OEM part number) sold by aftermarket resellers.
What he told me makes a lot of sense and I've been able to ascertain his information.
He said Bosch can only put the Porsche part number on a proprietary MAF destined to go to Porsche under a PO.
But, every MAF gets tested by the factory. Many MAFS don't make the test and they are set aside and returned to Bosch.
Bosch then has the right to sell them to aftermarket resellers.
So, when you purchase a new, in-its-box-Bosch $275 MAF from an aftermarket reseller you are getting a MAF that didn't make all of the tests. You may get lucky and get a MAF that barely failed one of the minimal parameters, but you can also get one that failed more than a few crucial parameters.
The factory MAF (from the dealer) can cost $500 but it will generally last at least twice as long as the aftermarket one.
YMMV.
Happy Boxstering,
Pedro