Checking Catalytic Converter

To check a one-piece front pipe and converter, remove the pipe and hold it vertically with the outlet down. Firmly tap the end on a block of wood, then turn the pipe over and tap the other end in the same manner. A knocking sound inside the converter housing indicates that the ceramic core has become dislodged, and the converter should be replaced.

In addition to the check above, a separate catalytic converter can be visually inspected by holding it up to a strong light and looking through both ends. If the core appears broken or melted down as shown in Fig. 4-16, the converter should be replaced.

Fig. 4-16.

Examples of catalytic converter cores showing severe meltdown (left) and minor meltdown (right).