The modern vehicle has 2 lambda sensors fitted, one before (Bank 1) and one after (Bank 2) the Catalytic Converter. The Bank 1 Lambda Sensor of your vehicle checks the air/fuel ratio and regulates the mix via the ECU to protect the catalytic converter and to reduce the emissions to the atmosphere. The Bank 2 Lambda sensor of your vehicle checks the resulting emissions after the process of the fumes through the Catalytic Converter. Both Lambda Sensors in your vehicle therefore have different tasks and result with different issues. It is necessary before ordering to know if it is the pre-cat or post-cat vehicle Lambda sensor you require.