Greetings everyone, can I ask for a little opinion. Why when i turn on ignition key ON but my throttlebody does not sound the stepper motor rotating? When i continue to start, the CEL is on and the car cannot be more than 2k rpm. When the engine running for about 30 minutes. I switched off the engine and restart CEL disappears and the symptoms continue to disappear. This will be happen once in a day only. TB and ECU is newly replaced. The wiring is new. Spark plug also i check got thre current. New fuel filter as well. Can anyone help me out on this issue. I got the code of P0121. But last time i send out to proton they change new TB. But can this TB be defect within 1 year?