You need the elegant suit
Texas Hold'em style poker is in Red Dead Redemption.
Put it on, play poker, when your dealing press the shown button to cheat. You have to balance a bar in the middle of the screen, if you get court someone at the table will challenge you to a deal.
You purchase it at the tailor in Thieves Landing and it will be possible to cheat at poker. see outfits in related link
No you can't. You have to work to unlock them. There is one cheat found in the bottom right corner of the newspapers which gives you a suit which allows you to cheat in poker games.
You find treasure maps by helping people with carts who are usually being attacked by bandits, help them and they will give you a map. When you have this map, search for the treasure chests
there are no cheat codes for red dead redemption online. That would ruin the competition.
your mom i know its weird but that's the cheat
There are no cheat codes for a car
there is no cheat for it, you must do the missions for it in your journal
a guy will just walk up to you and challenge you to a duel. A quicker way is to purchase the elegant suit cheat a poker and get caught but Goth2's answer is more usefull if you want an honour boost
Pick a new cheat code.
There isn't a cheat. You get it by doing this quest: Wild Horses, Tamed Passions.