State aims to make major changes after finding that nearly a third of older cars fail roadside smog checks within a year of passing at test stations.

February 25, 2010 | By Margot Roosevelt

Nearly a third of older-model cars stopped for roadside smog tests in Southern California failed them, despite having received a passing grade at inspection stations within a year, a state audit has found.

The results of those surprise inspections of 6,000 models manufactured before 1996 have led law enforcement officials to crack down on unscrupulous stations, step up fines and file more criminal charges.