Thermotec Throttle body hose Jetta (1.4TSI)

Engine Air Intake Hose
The engine air intake hose channels clean outside air through the air filter and into the intake manifold. Depending on whether your engine is naturally aspirated or turbocharged, these hoses are typically made from flexible plastic or rubber, which can degrade over time. Maintaining a clean and sealed air intake system is essential for proper combustion of the air/fuel mixture. A damaged or failing air intake hose can lead to reduced fuel efficiency, compromised engine performance, and improper fuel mixture, potentially causing damage to the engine.

Engine Air Intake Hose Failure Symptoms
Check engine light: The check engine light may come on and stay on, indicating a lean condition
Rough idle: The engine may run rough at idle and under load
Intake noises: Additional intake noises may be heard during acceleration as air rushes in between cracks on a broken intake hose
Poor fuel economy: If there is not enough air, the engine will demand more fuel to compensate, leading to poor fuel economy