The Air Intake Pre-Heater Hose is a component of the engine's air intake system that helps to warm the air before it enters the engine.

 This is important because warm air is less dense than cold air, which means that it contains less oxygen per unit volume. By warming the air, the air intake pre-heater hose helps to ensure that the engine receives the proper amount of oxygen for efficient combustion. This can improve fuel efficiency and reduce emissions. 

Additionally, the air intake pre-heater hose can help to prevent icing in the air intake system during cold weather conditions. This component is commonly found in cars, trucks, and SUVs that operate in cold weather environments.