Your ECU monitors the engine's air-fuel ratio thanks to the 2012 Juke oxygen sensor which can let the computer know when something is off. A bad sensor won't do this,risking damage to important parts like the catalytic converter,and it can turn on the Check Engine Light. By replacing this sensor,you can keep your engine running for maximum power and fuel efficiency,and minimum emissions. Shop 2012 Nissan Juke O2 sensors and get free next day delivery or same day pick up at your local store.