I was told the same thing today by a Car Mechanic... At first, I thought it was my battery but it's not. Every morning my car revs like crazy especially during cold start ups. Now that winter is here, it's even worse. The RPM is at 3.5 when I am driving at 35 km/hr but after a long while RPM goes down to 2. I am assuming I need a new Throttle Position Sensor. I hoping I am not the engine is not being damaged. Any comments please?