I've been through the eBay wringer on car parts. I also got a non-oe (FAE) oil pressure sensor from a reputable site. It is out of spec. It reads 1 bar with koeo and always reads 1 bar too high. I know the oil pressure is OK because I've tested with a pressure gauge on that port.

The pisser is, it has the Bosch markings on it! WTF! I have another one en route from Pelican Parts. The MB part number is the same as the Bosch but $40 higher. But yea, no more Ebay parts for me.

Side note, I did drop it of to an Indy and they had it for 2 weeks. They couldnt fix it but didnt charge me either.