California Catalytic Converter (Cat)Secrets to Passing & Reasons for Smog Test Failure

Update: 2018 August: 2 years and 10,000 miles since my last smog check PASS my numbers displayed as Measured\(Max allowed): @15mph HC 42\66, CO 0.05/0.57, NOx 14/487 (15mph HC is the hardest part for my car) @25mph HC 14\49, CO 0.02/0.55, NOx 3/774. Catalytic Converter replacement 1997 Saturn SW2 with Federal Emissions, Engine Family Group: VGM1.9VJGKGM which is NOT in the aftermarket database aka California Application Catalog. Note: if your car receives a special exemption you will be issued a "Referee label" that will let smog tech's know your vehicle is ok to test.