Do Percocets test the same as heroine?

If you are referring to drug testing, no. Percocet is oxycodone, while heroin is derived from morphine, and turns into morphine when metabolized in the liver. These drigs are derived from different opium alkaloids and will not report as the same thing. However, if the drug test is for the broader opioid/narcotic category, then they will both show up.