There are a couple of codes for different types of vapor leakage, depending on the severity of the leak, there's a so-called gross leak, then there's a minor type, which usually is the gas cap, unless the seal is so bad that during the self-test, it's contrued as a major(gross) leak. The gas cap is part of the evap system test, which checks your fuel system for vapor leakage, I believe every cold start, I could be wrong on the frequency, just guessing without consulting the book. Some systems use vacuum, some use a pump to pressurize the lines and then check them for leakdown, slow fast whatever. What is NTB?
Tuesday, February 13th, 2007 AT 6:10 PM