Volvo Repair: 86 240 DL Volvo emission problems, spark plug wire, magic potion

Question
I have an 86 240 Dl Volvo....160k miles...four door sedan...
It will not pass inspection due to high CO levels, all other areas pass with flying colors, the mechanic mentioned the NO levels were lower then normal as well, but still WELL below the normal passing rate.
No one seems to have an emission dianostic machine in my small rural area, I have a man that works on Volvos but would like some areas to direct him to look instead of him tearing the whole car apart.
Any ideas?

Answer
Hi Kristen...
           Hmmm what can we do to make it pass..?
          I don't have lots of info to go on..it could be the cat.converter?...which needs to be replaced...buy parts on internet...SUPER savings on price.
           Many auto parts stores sell a magic potion in a bottle that guarantees that it will pass emissions...(no joke)...I haven't tried it....maybe a simple problem....loose or broken vacuum line near engine...bad spark plug wire....the list goes on.
                 Good luck,
                            Bilbo