Watch Out for Debris in Certain GM Vehicles
Certain 2019 and prior GM vehicles (2017 Chevy Caprice, for example) may be equipped with a new style of catalytic converter known as the close-coupled catalytic converter.
If an engine breakdown or non-function occurs such as broken intake/exhaust valves, piston failure, etc., debris may be deposited in the converter through the exhaust ports.
If the engine is non-functioning due to a severe over-heat event, damage to the ceramic brick in the converter may occur. This may result in ceramic debris being drawn into the engine through the cylinder head exhaust ports.
If a replacement engine is installed, the replacement engine may fail due to debris. When replacing an engine, the catalytic converter must be inspected.