Filiberto Cervantes has already separated from his wife and kids, lost his car, moved into his truck and says he subsists largely on a diet of $1 cheese burritos. But Jan. 1 looms like a date with the grim reaper himself. ... Cervantes is among thousands of truckers servicing the Los Angeles-Long Beach port complex who are facing a day of reckoning this New Year's. That's because Jan. 1 is the day new clean-air guidelines go into effect at the ports, banning all pre-1994 trucks -- as well as 1994-2003 rigs that have not been retrofitted with costly diesel particulate...