What might cause ignition of undercoating and interior carpet in a vehicle?

Excessive heat from the catalytic converter is a likely cause of ignition of undercoating and interior carpet in a vehicle. The catalytic converter is a component of the exhaust system designed to reduce harmful emissions. During normal operation, it can reach very high temperatures, especially if the vehicle is driven aggressively or if there is an issue with the engine that causes it to run rich.

When temperatures exceed the ignition point of the materials surrounding the catalytic converter, such as the carpet and undercoating, spontaneous ignition can occur. This is particularly relevant in vehicles where the undercoating is flammable or when the carpet is made from synthetic fibers, which can ignite if exposed to sufficient heat.

Understanding this aspect of vehicle operation is crucial for fire investigation technicians, as it highlights the importance of examining heat sources and their potential interactions with combustible materials in a vehicle fire scenario.