If your Chevrolet Impala failed the emissions test due to high NOX, the EGR Valve is most likely the issue. If your Chevrolet is running rough or has poor fuel mileage, replace the Impala EGR Valve and gasket.
Do not buy the cheap no name remanufactured or rebuilt Chevrolet Impala electronic control units, as in our experience most of these ecu’s don’t even work right out of the box. We also carry programmable Chevrolet Impala control units from AEM that allows you to custom program your Chevrolet Impala ignition and fuel system.
Replace your faulty Chevrolet Impala Mass Air Flow Sensor with a Genuine or OE Bosch Unit to keep your Chevrolet running like new.
The Chevrolet Impala Oxygen sensor is a critical part of the emmision control system and should be replaced as soon as it fails. Make sure to check the Chevrolet Impala diagnosics codes for proper replacement of the O2 Sensor.