The culprit will probably be the Idle Control Valve (ICV) which is located on the top of the inlet manifold. The ICV acts as a gate allowing varying amounts of air into the engine. However they are known to stick. Then they either let too much air into the engine, possibly causing high revs, or not enough starving it of air and causing the engine to almost or actually cut out.
Hi, Im new to this forum and have a 2001 Scenic. Canterjohn or any other member - can you please describe what the ICV looks like and how this "sticking" can be fixed.