Paseo Idle and Noise

[paseofreak2007]

I have a 1993 paseo and am having a couple of problems, just wondering if anyone could offer some help or suggestions.
First, I am having problems with the idle on my paseo. The idle will fluctuate when the clutch is disengaged and it is not in gear. Like when I am stopped at a stop light it will be reving up and down without stopping untill I start off again and engage the clutch. Thinking it might be something with the idle/oxygen sensor or something like that but i'm not sure.
Secondly, the other day I started up my paseo and it started growling like there was a hole in the muffler or something. I looked and could not find any problems or holes in the pipe or anything. Also the exhaust smells almost like 2-stroke or snowmobile exhaust. I think it might be the catylitic converter because the noise sounds like it is coming from the front of the car by the engine. Any help would be appreciated.