El Pollo Loco, a chain of grilled chicken restaurants in the Southwest, is trying to build buzz by challenging rival KFC to a taste test of its grilled items. El Pollo Loco claims calls have been fielded from KFC parent Yum! Brands on a toll-free number advertised in a TV spot calling for the contest. And it has posted a YouTube video mocking its larger rival. KFC says it's been "grilling" its workers to find out if they're involved.