What to Do When Vehicle Inspection Shows Excessive CO in Exhaust?
2 Answers
If the CO level in the exhaust fails the inspection, the solution is to clean or replace the three-way catalytic converter. The three-way catalytic converter is a crucial component for processing vehicle exhaust. The gases produced after combustion must pass through it for conversion before being released from the vehicle. During this process, harmful gases such as CO and HC+NOX (hydrocarbons and nitrogen oxides) are converted into harmless substances like carbon dioxide and nitrogen. Here is additional information: Reasons for cleaning or replacing the three-way catalytic converter: Primarily, during use, the process of handling combustion gases can lead to carbon buildup, clogging, poisoning, or failure of the three-way catalytic converter. Such issues reduce or even eliminate its conversion capability, resulting in excessive vehicle exhaust emissions. Spark plugs can also affect exhaust emissions: The ignition system, including spark plugs and ignition coils, is another significant cause of excessive exhaust emissions. Over time, spark plugs can accumulate carbon deposits or become eroded, deteriorating their performance. This leads to incomplete combustion of gases in the combustion chamber, increasing the presence of toxic gases in the exhaust. If carbon deposits are present on the spark plugs, they can be cleaned with a cleaning agent and sanded with sandpaper to restore their activity. If erosion occurs, replacement is necessary.
Don't panic if your vehicle fails the CO emission test. The issue is usually caused by incomplete engine combustion, such as a clogged air filter restricting airflow or faulty oxygen sensor signals affecting the fuel mixture. Another possibility is carbon buildup in the catalytic converter, which is crucial for exhaust purification. First, try DIY checks: replace the air filter (it's inexpensive and easy with online tutorials). If that doesn't work, visit a repair shop for professional diagnostics—they may clean fuel injectors or throttle bodies. Always use recommended fuel grades; cheap gas causes carbon buildup. Annual maintenance checks can prevent recurrence.
