RPM Problem driving me mad
I have a 2001 Camaro SS and lately I've been having an issue which I am going to try to explain as best I can. It usually takes about 15-20 minutes of driving before it starts giving me trouble. At that point if I am driving and say I take my foot off the gas and coast, then push my clutch in, the RPMs go up a few hundred then slowly fall. The best way to describe it is as if the throttle is sticking but everything along the throttle cable seems fine as far as i can tell. Also once this starts to happen the idle of my car is higher. Instead of idling at like 700-800 or whatever RPM, it's more like 1200. It sounds as if the foot is slightly on the gas pedal.
I had read through the service manual and one of the simplest suggestions was more or less checking the air filter. I could have been reading under the wrong section of the manual but mine was rather dirty so I cleaned it and oiled it (I have the K&N FIPK).
I would really appreciate if someone gave me a starting idea as to where to look or turn to solve this problem. Sadly I'm thinking about getting rid of my camaro for a GTO but with problems like this, the dealership is most likely going to try and drop the value of my car more so I would like to get stupid problems like this sorted out before I attempt to use it as a trade in. Love my camaro but car seats just don't work out too well in the back of it heh.
Thanks for any help.

