Rheem Furnace Problem

[mahesh]

I have a rheem gas furnace thats just 2 years old. its giving strange smell - like a burnt paper or something and making very loud noise. I had a contractor look at it - he opened it and said every thing looks fine and it started working just fine. The guy installed a CO sensor in our master bedroom. Now again - the heat was not on all day, i just turned it on, I am getting this problem.

I am at a point can't figure out exactly whats going on. I have little or no knowledge about furnaces - appreciate anyone could tell me what the problem is or what i should be looking for.

thanks in advance.

mahesh.