What must be true about the original configuration for catalysts, filters, and traps to pass visual inspection?

• A. Must be in the original configuration with the same number of devices in place, unless CARB approved/exempted
• B. Devices may be removed if the system remains functional
• C. The number of devices does not affect the inspection result
• D. Only the location of devices must be preserved, not the count

Answer: (A)

The main idea is that a visual inspection checks the vehicle’s emission-control hardware against what the manufacturer installed. You must have the original configuration intact, meaning the same number of catalysts, filters, and traps in place, unless CARB has approved an exemption. This matters because removing or changing the number of devices changes the system’s design and its ability to control emissions, which the inspection is meant to verify. So simply keeping where the devices are isn’t enough if the count isn’t the original and unless an official CARB exemption exists.