Heated Catalyst Efficiency Below Threshold (Bank 1)

Yes. Driving is safe with this code. The heated catalyst is underperforming, increasing emissions output but not affecting engine operation.

A heated catalyst has an electric heating element that warms it to operating temperature faster than exhaust heat alone. This is common on hybrid vehicles where the engine may not run continuously.

Hybrid engines cycle on and off frequently, so the catalyst cools down between engine-on periods. The heater compensates, but if it fails, the catalyst cannot maintain efficiency during frequent cycling.

California's OBD II regulation — the rule that defines when an OBD system must set an emissions code — requires the system to flag the catalyst when its conversion capability drops far enough that Non-Methane Organic Gas emissions would exceed 1.75 times the FTP full-useful-life standard (Title 13 CCR 1968.2, section (e)(1.2)). So the code is not reporting that the converter is dead; it is reporting that measured efficiency crossed the line the monitor was calibrated to. This is the threshold the monitor is designed around, not a description of your specific fault — the regulation says what the system must detect, not how to find it on your vehicle.