I just noticed the problem. When i take my foot off of the gas the car tends to hold the current rpm then drop to 2k or so until i come to a complete stop. What could cause this? i have a cel and its code 21 which is the o2 sensor, but i dont think that would cause the problem. TIA

mine does that when it's warming up. It's like it won't settle down completely until you come to a complete stop. I believe it's normal while warming up, but not all the time.

jeff