Did a maintenance on a gas furnace. Cleaned off the flame sensor also cleaned out the back burner compartment and the blower motor housing. Swapped out to 16 x 20 x 1 filter. Did a combustion test Co level was 49 and the O2 level was 11.2. Also do the amp reading on the inducer motor and blower motor does meet the furnace spec sheet. System is operating properly at this point. M#KG7SA 090C-24B1 s#KGG170709407