The 2003 Toyota 4Runner has 5 recalls, the most serious being a fuel system defect where a leaking component on the fuel rail can allow gasoline to escape near heat sources and start an engine compartment fire. This issue affects V6-equipped vehicles and has been filed in multiple records, but describes the same underlying problem. A separate safety concern involves the side curtain airbags, which can deploy unexpectedly and raise the risk of occupant injury. There is also a recall covering floor mats: an unsecured or incompatible driver's floor mat can trap the accelerator pedal in the fully pressed position, making the vehicle difficult to slow or stop. On the chassis side, certain vehicles processed through a Florida port with an alloy wheel upgrade may have mismatched wheel nuts that can damage the spare wheel if it is ever installed, eventually allowing the wheel to loosen while driving.