90% of the time its from the oil that was dripped down from the oil filter being changed. I don't know if you ever did your own oil change before but the oil filter is right about the cat pipes and so when the filter is taken off a little bit of the oil drips down and hits the pipes. You are probably smelling burning oil which is fine, just drive it like for 1 more week until all the oil is burned off from the pipes. Then see if the smell is still there.