a WARNING about ebay aftermarket MAF sensors
 

Ok just a little note on these aftermarket sensors

I bought mine from MPG Autoparts, 89.99. First, let me tell everyone how they are made. The aftermarket sensors you are buying on ebay are modified used sensors. That's correct. They are not even refurbished. If you look at the sensor case, you can see where it was cut apart and glued back together. Furthermore, the sensing element is fundamentally different. The "manufacturer" cuts a small window in the original sensing element film through which they solder a diode.

Now I will tell you how they work. I purchased one to fix my CEL (voltage too low). It was nothing but a NIGHTMARE. Every time I would leave my car overnight, the car would not start until I took the sensor out of the engine and cleaned it with alcohol spirits. This went on for days. I got another sensor from the manufacturer, and while it is better, it is still unacceptably bad. When I start the car, the sensor needs time to 'warm up' or something, because if I just try to take off right after starting, the car will sputter and even DETONATE.. yes, this ****************ty sensor actually causes pinging, I am not kidding. I would love to sue these ****************************s for making products that cause detonation.

(There is nothing else wrong with my car. Any problems are entirely related to the sensors from MPG auto parts, since when reinstalling my old, original porsche MAF, all of the above symptoms disappeared (except for check engine light of course). I have tried this repeatedly.

DO NOT BUY EBAY MAFS OR AT LEAST NOT FROM MPG AUTO PARTS OR YOU RISK BEING STRANDED LIKE I WAS OR EVEN RUINING YOUR MOTOR

Not all MAFs are created equal...
 

... 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

Yep, ebay is useful for lots of stuff... just not functional Porsche parts. Caveat emptor.

I agree MIKSTEW regarding MPG Autoparts, they're a real sketchy outfit . Without getting into too much detail, I decided to give one of their "clone" sensors a try a few months back . And, as it turned out, it was the wrong part . The long and short of it was, that I had to jump through hoops in order to get a refund . On the other hand, I purchased an aftermarket MAF sensor from another seller on eBay (whom, incidentally, was also an authorized Bosch dealer) for $89.00. After carefully scrutinizing it, it was virtually identical to the oem part in every way . And, so far it has worked perfectly. No CEL, and my vehicle runs great . When you think about it, a MAF sensor nothing more than a two cent piece of plastic, along with a glorified paper clip and a piece of plastic film . If an aftermarket company spends a little time on detail, there's no reason why they can't replicate the same part that Bosch produces .

The bottom line is that you almost never get what you don't pay for. If it costs too much less, or seems too good to be true, it is.

That's not always true . I spare no expense when it comes to my boxster . But, for $89.00 (plus a one year warranty), I successfully solved my MAF problem for cheap . I am convinced that the aftermarket sensor that I purchased on eBay is the exact equivalent to the Bosch part for a mere fraction of the cost .