If your Chevrolet Cavalier 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 Cavalier EGR Valve and gasket.
Do not buy the cheap no name remanufactured or rebuilt Chevrolet Cavalier 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 Cavalier control units from AEM that allows you to custom program your Chevrolet Cavalier ignition and fuel system.
The Chevrolet Cavalier 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 Cavalier diagnosics codes for proper replacement of the O2 Sensor.