Used throughout Manchester, Salford, Bolton, and possibly other areas. Can mean a bad/sticky situation, especially one involving pigs.
It can also be applied to a person who does something or acts bait, confusingly, or disappointingly.
1):
Guy 1: "Shit, I've just spilt the bong mix on the floor lad!"
Guy 2: "No way, that's bangers that!"
2):
Guy 1: "Check this fat Q I just got"
Guy 2: Put that away, there's a fucking police car driving up, you're bangers you bro"