Evaporative emissions leak check module with VOC measurement

A leak detection module may include a housing and a canister valve solenoid (CVS) arranged within the housing and in fluid communication along a first fluid passageway between canister and atmospheric ports. The leak detection module may include a second fluid passageway in parallel with the first fluid passageway and fluidly connected to the canister and atmospheric ports. A CVS check valve is arranged in the second fluid passageway and a volatile organic compound (VOC) gas sensor is arranged in one of the first and second passageways, configured to measure the concentration of hydrocarbons (HC) therethrough. A mass flow meter is arranged in one of the first and second passageways to determine a mass flow rate from the canister port to the atmospheric port. A controller measures the quality of the emissions by monitoring the HC and communicates the result to a base station.