It was a real stinker of a crash.

A city bus rear-ended a tanker truck loaded with kitchen grease in Brooklyn yesterday morning, leaving 16 people injured — and an overpowering stench at the intersection of Nostrand Avenue and Lincoln Place in Crown Heights.

“It smelled horrible, like old chicken grease,” said Alfonso Waters, 54.

Residents said the bus driver didn’t open the bus’ rear door, forcing frightened passengers to scramble out the front exit.