Catalytic Converter: Testing and Inspection

By unscrewing the test screws on the exhaust manifold and attaching BMW adapter #13 0 100 or substitute, the efficiency of the catalytic converter can be checked by measuring and comparing the CO content before and after the converter. The CO content after the catalytic converter must be substantially lower then the CO content before the converter. Reconnect test screws on the exhaust manifold.
An additional testing method can be used to check the catalytic converter visually. Remove the catalytic converter from the vehicle. With either opening toward a light source, inspect the ceramic insert from both sides. If the ceramic insert is broken, melted or clogged the catalytic converter must be replaced.