Fits for: For 2012-13 Chevrolet Sonic For 2011-15 Chevrolet Cruze For 2013 Chevrolet TRAX Specification: OE???34-4528, 234-4529 Features: *Function 1.The front oxygen sensor is to detect the air-fuel ratio of the engine in different working conditions. 2.The rear oxygen sensor is mainly to detect whether the three-way catalytic converter works normally. * 100% test before shipment. * The reduction of harmful emissions. * The increasing of fuel economy. * The improvement of engine performance. * Prevent premature failure of the catalytic converter. Packaging include: Oxygen Sensor*2(Upstream+Downstream) .
