You can always visit any smog station and ask for a smog check "pretest". During a smog check pretest your Cadillac smog check results will be sent to the State however the results can not be used against your vehicle. For instance if after the smog check the results showed your Cadillac to be a gross polluter, it would not be registered as a gross polluter with the State. Also a smog check station might charge less for a smog check pretest.
HC is caused due to misfires and vacuum leaks. NO is caused due to high engine combustion temperatures.