My 1981 FJ60 is failing the Colorado Emissions for CO% at 2500 rpm. I changed the spark plugs, oil and air cleaner and the FJ60 failed the CO% was 1.55 (limit 1.50) Next I added a product called sea foam to clean the carburetor and engine (into carb and gas tank). And had a retest after running two tanks of fuel through it and added some no smoke from NAPA to the oil (was smoking some). Now it really failed, blowing dark smoke and the CO% was over 4.5 (limit 1.50) I decided that the cleaner trashed the carburetor so I rebuilt it with a kester (sp) kit. It no longer smokes but still fails the emissions. The CO% is down to 3.5 range. Any suggestions as to what the solvent based cleaner could have done/messed up. I am lost as to what could be causing this problem!