This document describes a system to detect alcohol levels in a driver's breath and prevent vehicle operation if intoxicated. The system uses an MQ-6 alcohol sensor connected to an Arduino Uno microcontroller. If the sensor detects alcohol levels above a threshold, the Arduino triggers a buzzer and disables a simulated vehicle engine. The system is a prototype that demonstrates automatically locking the engine if high alcohol is detected to prevent drunk driving. It provides safety by not allowing operation of the vehicle when the driver has consumed alcohol over the legal limit.