Can you use a flashed iphone for Metro PCS?

I saw an ad on Craigslist for a flashed metro pcs iPhone, I was wondering if it would actually work properly with metro PC'S? How does it work.

Bring it to a unlocking store they will help you

Don't believe it. Craigslist is a boon for stolen iPhones. You're lured in with a really cheap price--that's the dead give-away. It's locked to an old network, and probably has iCloud activation lock turned on by the previous owner so it's a ripoff. If you attempt it make the guy prove he can get into the phone. If they can't, walk away. Best luck.