Use only Honda OE quality replacement Catalytic Converters to keek your Honda Prelude in the best running condition. DriveWire sells only California legal Prelude OBD-II Converters.
If your Honda Prelude failed the emissions test due to high NOX, the EGR Valve is most likely the issue. If your Honda is running rough or has poor fuel mileage, replace the Prelude EGR Valve and gasket.
Do not buy the cheap no name remanufactured or rebuilt Honda Prelude 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 Honda Prelude control units from AEM that allows you to custom program your Honda Prelude ignition and fuel system.
The Honda Prelude 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 Honda Prelude diagnosics codes for proper replacement of the O2 Sensor.