Lexus GS300 high idle issue in the morning and after extended sitting, suspecting bad ECU on Lexus GS300

Some Lexus GS300 owners report experiencing high idle issues, particularly in the morning or after extended periods of inactivity, which may be linked to a malfunctioning ECU. These owners note that high idle can stem from various factors, including a faulty VVT system, MAF sensor, or air intake temperature sensor. A malfunctioning ECU can lead to irregular engine behavior, affecting idle speed and potentially causing rough idle, misfires, loss of power, and poor fuel economy due to incorrect information being sent to the engine sensors. It is crucial for owners to recognize that consistently high idle speeds indicate underlying problems that require attention, and thorough diagnostics should be conducted to identify all potential causes before concluding that the ECU is the primary issue.