rav4 2017Low rpm on idle when stopped

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your vehicle. A couple of things could cause your RAV4's fluctuating idle RPM. Since you've already changed the spark plugs, installed a new alternator, and cleaned the throttle body, it might be worth performing a diagnostic scan to check for throttle position sensor codes. Additionally, check for vacuum leaks in the intake system, as even a tiny leak can cause fluctuations in idle. If the engine speed seems to begin dropping while braking, an internal leak in the brake booster may be the cause. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!