CO sensors have a limited lifespan before they must be replaced typically every 5 years or so. Wen, $53: https://wenproducts.com/products/gn625ix-1430-co-senso

CO sensors have a limited lifespan before they must be replaced typically every 5 years or so. Wen, $53: https://wenproducts.com/products/gn625ix-1430-co-sensor-module-for-wen-gn625ix https://wenproducts.com/products/gn625ix-1430-co-sensor-modu... Generac, $169: https://gen-parts.com/products/generac-generator-part-10000046048-kit-co-sense-module-service https://gen-parts.com/products/generac-generator-part-100000... This is a not-insubstantial continuous cost adder. And given these modules are almost certainly proprietary, you're at the mercy of the manufacturer in terms of parts availability and cost. I would expect manufacturers to love this; this has basically converted generators into a subscription service (albeit with a 5-7 year renewal period). And, a potential avenue for planned obsolescence. All they have to do is stop producing the replacement sensor, and those generators will be bricked. And before you think about trying to disable it: The regulations specifically require that the generator ensure the sensor is functional, or the generator must prevent itself from running. The generator wiring etc must be tamper resistant, not accessible by regular tools, to prevent a user from attempting to bypass it. So, now the generator will have some portion of it as tamper-resistant, by law. I wonder how that will affect reparability?