Question about DS flash cards

IF im running a game through a DS flash card on a real DS, can i play games like metriod and mario kart online?
thanks in advance

Yes, flashcarts work exactly the same as a original game cartridge, so yes, you can go online with games. Some flashcarts have problems going online or wifi with a few games such as Mario Kart, but this was a long time ago, so the newer firmware for flashcarts should be able to go online with all wifi capable games.

ok thanks
do roms played on the DS ever have glitches that regularly wouldnt occur if you were playing the actual game?

It depends on the flashcart and how fast your card is (MicroSD etc.), but you shouldn't have a problem, just about all games run perfectly on most flashcarts.

thank you for the fast reply and your answers