What threshold can cause a vehicle to fail due to carbon monoxide emissions?

The threshold that can cause a vehicle to fail due to carbon monoxide emissions is exceeding the established limit for carbon monoxide (CO) set by the state. This limit is determined based on health and environmental standards to protect the public and the atmosphere. When a vehicle emits CO levels that surpass these limits, it indicates inefficient combustion processes or potential issues within the vehicle's emission control systems. Such excess emissions are a concern because carbon monoxide is a harmful pollutant that can contribute to air quality issues and pose health risks.

The established limits are based on extensive research and analysis, and they are designed to ensure that vehicles operate within safe environmental standards. Therefore, if a vehicle fails to comply with these limits, it is necessary for maintenance or repair to be conducted so that it can reduce its emissions to acceptable levels, ultimately ensuring a cleaner environment and better public health.