II know that through an emmissions sniffer test you can tell how a vehicle is running. I know HC readings tell you how effectively the fuel is being burned (err, how rich or lean the mixture is). NOx readings are an indication of ignition timing if I remember right. What about the other readings?
These are the results from my 1991 Cavalier station wagon. It has a built 3.1L V6 that's been bored 0.030" over, it's got a custom Crower camshaft, everything has been ported, polished, and port matched, it's got 320 cc RC Engineering injectors, a Haltech E6GMX standalone computer, and a Garrett 46 trim T3/T4 turbocharger. The motor currently has about 15,000 miles on the rebuild.
co = carbon monoxide - goes up when youre running rich, part ofburnt hydrocarbons
co2 = carbon dioxide - part of burnt hydrocarbons, other part is water vapor
o2 = oxygen - oxygen not used by combustion
nox = oxides of nitrogen - goes up in excessive combustion temps
but i'm guessing its not running rich because youre 02% (oxygen) also went up and co is still low. apparently your engine is less efficient than normal at lower rpm(15mph test). my guess would be that your cam has a greater overlap than stock which could cause this.