I drive a 2001 Hyundai Accent with 257k miles. It started revving on its own just recently. It has a manual transmission and has been running just fine until now.
I've been told to check the airbox, the vacuum hose connecting to the airbox (for cracks) and the spark plugs. I've also been told to add some additives to the fuel in order to clean the injectors.
What do you guys think?