Plain-English answers to every California smog check question
Modified Specific
I have an aftermarket exhaust — will I pass smog?Only if the part carries a CARB Executive Order (EO) number for your specific vehicle — the EO number is what makes it smog-legal when your car is tested at a smog station.
What if I swapped my engine?Each component must be CARB-legal with proper EO documentation.
Will tuned ECU pass smog?Only if the tune has a CARB EO number.