Scott,
Not to confuse the issue but high HC content can also be the
result of a lean condition. Weak mixtures may burn inefficiently
or not at all resulting in "raw" fuel like components at the
tailpipe. Back when one could actually find and adjust the
idle mixture screw on ones carburetor (when you had one), it
was not uncommon for neophytes (like me) to "lean out" the
idle mixture before heading out to the smog station. The idea
was that this leaning out might reduce tailpipe emissions.
More often than not what actually happened was an increase in
HC emissions because of the overly lean condition. Your best
bet is to adjust the idle miture screw as indicated by the
vehicle manufacturer (no charge for this revolutionary idea).
I'm not sure how a lean idle screw setting would effect CO,
anybody else out there know?
Good luck,
Frank Marrone at marrone@optilink.com
|