An automotive leak detection system that includes means for forming a secure, leak-proof interconnection between a source of pressurized leak detection vapor and the automobile engine's air induction system ducting or hose. The system includes a sealing mechanism that is specially contoured and configured to matingly interconnect about the opening defined about the distal-most end of the air induction system ducting or hose such that the sealing device and hose form a secure, leak-proof interconnection. The sealing device may be provided with a customized periphery that is designed to correspond and matingly engage with the footprint or specific configuration of the distal end of the air induction system ducting or hose of a specific car manufacturer and/or specific make and model air induction system ducting or system.