Mr. Stenchy: Experiment 254

Lilo and Stitch have captured a new experiment, #254. He is insanely cute too, and charms all of Lilo's friends. Stitch is jealous though, so at the first chance he gets, he lets Gantu capture him. As luck would have it, 42 hours after the experiment's activation, Mr. Stenchy releases such a foul stench, the area he releases it in is uninhabitable for decades. But without knowing of when Mr. Stenchy was activated, how will Lilo and Stitch save him before he releases the smell?