Which model year vehicles must receive a Low-Pressure Fuel Evaporative Test (LPFET)?

• A. Model year 1996 and newer.
• B. Model year 2000 and newer.
• C. Model year 1986 and newer.
• D. All model years.

Answer: (A)

LPFET is used to verify the tightness of the evaporative emission control system on newer vehicles. Starting with 1996 models, vehicles adopted more advanced EVAP systems and OBD-II diagnostics, which require a low-pressure vacuum test to detect leaks that could allow fuel vapors to escape. The test applies a controlled low pressure to the system and checks how quickly the pressure decays; a leak above the allowed limit indicates a fault in components like hoses, the canister, or the purge valve. Because these design updates and testing requirements began with model year 1996, the LPFET is mandated for 1996 and newer vehicles, while older model years use different testing methods.