This sounds like it was written for out of state purchases, but may apply to cases such as yours:

"INSPECTION In order to maintain safe highways, the once-a-year safety inspection system requires that all used vehicles be inspected within 10 days of sale unless a valid inspection sticker is displayed on the vehicle. The buyer is responsible for having the vehicle inspected, which can be done at any Pennsylvania certified inspection station. If the vehicle is registered in an area of the commonwealth participating in the Emissions Inspection Program, the vehicle will also be required to have an emissions inspection"

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.dot.state.pa.us/public/dvspubsforms/bmv/bmv%2520fact%2520sheets/fs-buysell.pdf&ved=2ahUKEwiZ39uw_Z38AhUBp3IEHWlFDPAQFnoECBsQAQ&usg=AOvVaw2Oq4BMyaVGbkztZyjfnOuv