What Happens When the Intake Manifold Leaks?

[Darren]

Intake manifold leakage can lead to the following symptoms: Abnormal Pressure Detection: The pressure inside the intake manifold will change because it does not match the normal intake channel, resulting in abnormal pressure detection. Lean Air-Fuel Mixture: The intake air volume increases too much, and since the fuel injection amount is primarily determined by the intake volume. Higher Idle Speed: With more air, the fuel injection amount will increase accordingly, causing the idle speed to rise. Alternatively, due to irregular intake from the leakage point, the idle speed may fluctuate between high and low. Fluctuating Fuel Injection: Another scenario is when the ECU detects the idle state through the throttle sensor, leading to fluctuating fuel injection. If the leakage is not severe, it may only result in a slightly higher idle speed without causing erratic engine speed.