Scion xB very low idle at 400 RPM, needs adjustment procedure on Scion xB

Some Scion xB owners report experiencing very low idle issues, with RPMs dropping to around 400. These problems may stem from various factors, including vacuum leaks that can lead to rough idling, necessitating a thorough inspection of vacuum lines and the intake manifold. Additionally, a dirty throttle body is often cited as a contributor to low idle, and cleaning it may improve airflow and engine performance. Worn or fouled spark plugs can also cause rough idling, prompting owners to check and replace them as needed. Furthermore, low fuel pressure can impact engine performance, so testing the fuel pressure is advisable. Some owners also find that low compression in the engine cylinders contributes to the issue, making a compression test a valuable diagnostic step. Lastly, resetting the Engine Control Unit (ECU) by disconnecting the battery can help recalibrate the engine's performance. Addressing these concerns promptly can lead to improved performance and idle speed in the Scion xB.