Preformed furnace c+t Removed and cleaned burners and flame sensor then reinstalled. (No oxidation) Checked filter (good). Left new one. Checked igniter (preforming well at this time) Checked ignition sequence (good) Checked safety systems (flame sensor, pressure switch, high limit) Checked and cleaned blower motor Inspected electrical circuit board Checked and adjusted gas pressures (now 3.5 wci) Checked furnace drains (good) Checked CO2 in flue and in airstream (all levels at normal) Restarted system Furnace and controls working well at this time Completed