Chevrolet Silverado Rear Bumper Park Assist Sensors, had one sensor go bad and dealer wanted $250.00 for one of them. I said no!! I found four pack sensor online with same exact part number and I changed out sensor but still not work, took truck back two dealer and now they said there are two more bad so I gave the three I had in the pack, they now say the computer do not see the sensors and call the sensors I bought aftermarket, so confused when the match the same part number as the old sensors from the factory, anyone have suggestion? Is the dealer pulling the wool over my eyes?