The engine may stall without warning due to a faulty fuel pump relay.
The fuel rail hose under the hood may leak fuel due to a faulty seal connection. This would cause a fire hazard.
Vehicle control may be lost unexpectedly due to a fault with the dirveshaft / rear axle.
The instrument cluster could malfunction and become inoperative, causing the gauges to oscillate at zero and keep the vehicle theft alarm indicator illuminated. This could increase risk of a crash.