Every California smog check term and question, plainly defined
What should I know about Chevrolet smog checks in California?
Chevrolet vehicles generally pass California smog without issue, but V8 models equipped with Active Fuel Management (AFM) cylinder deactivation are at elevated risk of misfire codes that cause smog failure — especially if the vehicle has high mileage or oil consumption.
Active Fuel Management (AFM) on 5.3L and 6.2L V8 engines (Silverado 1500, Tahoe, Suburban, Camaro SS) causes lifter failures that generate misfire codes P0300-P0308 — a guaranteed smog fail
AFM lifter issues typically emerge between 80,000 and 150,000 miles; oil consumption is a leading indicator
2003-2009 Silverado/Tahoe with 5.3L: catalytic converter degradation on high-mileage examples is common after AFM lifter events
Equinox 2.4L (2010-2017): oil consumption issues can cause fouled O2 sensors and cat converter contamination
Silverado 2500HD/3500HD Duramax 6.6L diesel: intact DPF, EGR, and DEF required — any delete or aftermarket tuner that alters emissions = automatic fail
Colorado and Canyon 2.8L Duramax diesel: same DPF/EGR requirement as HD trucks
Per BAR inspection data and GM AFM technical service bulletins.