Smog Check Manual – Visual Inspection Practice Test

EVAP bypass or removal shows up visually as damage or disconnection in the evaporative system plumbing. The purge valve is the component that routes fuel vapors from the charcoal canister to the intake. If that valve is missing or the hoses connected to it are open or not connected, you’ll see unattached hoses or missing fittings, which are clear signs that the EVAP path has been bypassed or removed. A missing gas cap is a symptom of an evaporative leak, but it doesn’t demonstrate a bypass of the EVAP system itself. Replacing the purged canister could involve changes to the system, but by itself it doesn’t prove that the EVAP pathway has been bypassed unless hoses or fittings are left disconnected. Relocating an O2 sensor has no direct impact on the EVAP system, so it isn’t an indicator of EVAP bypass.