Here is another site with very useful info on the 5 gases present in exhaust. The amount of each present indicates what kind of problem exists. Perhaps take a look.

5 gases present in exhaust, what they mean.


BlackPantherSVT
2000 Contour SVT
Black with Midnight leather
#2075 of 2150
Mods:
K&N drop-N
Champion double-platinum plugz
"Mystery Mod"
Resonator replaced: Glasspack