+18 Does Check Engine Light Affect Emissions Test Ideas. While there are many varying reasons why your check engine light is on, two of the most common reasons that directly relate to emissions include a faulty oxygen sensor and a damaged catalytic converter. Web the presence of a check engine light can have an effect on the results of an emissions test.
A broken sensor can also turn on the eml. If you have an older model vehicle with an obd system, loose connection, or poorly wired electromagnetic compatibility (emc), it might be a significant reason for a failed emission test. When your check engine light illuminates, it indicates that there is a problem with your vehicle’s emissions system.
