Popping on deacceleration

So I’m looking at buying my first turbo motor and when I test drove it there was a popping noise during deacceleration. What causes this? I have heard it before on some non turbo cars

depends, its backfire usually.
its unburnt fuel being ignited by the hot exhaust pipe, usually.
one cause is leaky valves, so have the typical compression, leak-down tests done before you buy. one cause is extreme rich conditions off throttle (from a poor tune or piggy back electronics that only work at WOT), try to get a wide-band o2 sensor and see what it reads. this is why SRT4s pop and gurgle when you lift throttle.

most turbo cars will backfire, most high compression/big cam motors will too. more power= more fuel, more fuel= more backfire.

My car backfires and gurgles when im decelerating and i barely rest my foot on the gas, it starts to pop and gurgle all crazy like. sounds like a beast. lol.