I have 1993 Volvo 240 in almost perect condition here in California. The car has never failed any Smog Test. Recently, I had the car tested for Smog emissions. It passed all emissions test except for the "Fuel Evap Test" which it has never failed. Can anyone offer any advice on diagnosing a potential leak in the system? As I understand it, the Evaporative Emission Control basically provides a vent for the fuel tank that traps fuel vapors in a canister filled with activated charcoal. The vapors are later drawn into the air intake system and routed into the engine. I have had no symptoms or excessive fuel evaporation. I suspect that it may be a bad hose or loose fitting possibly causing a slight leak. I have head that there is a 'smoke test' for this issue. Has anyone ever experienced this problem? What would be the best way to find the leak and fix it?... The Smog Test Station pressurizes the fuel tank w/nitrogen and holds the pressure for a specified period to detect a leak in the system by checking for a pressure drop.

Thanks in advance for any advice.

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