Furnace clean and tune. Cycled system. Ch3cked heat exchanger, ok. Checked, removed, and cleaned burners and flame sensor. Both were ok. Checked and tightened electrical connections and clamps. Found clamp loose which was causing some minor leaking leading to some rust buildup on bottom of burner compartment. Found a few wires loose. Clamped and tightened those up. Checked and cleared drain lines. Checked and adjusted gas pressures to maximize efficiency. Preformed combustion test. Exhaust numbers were normal. No CO found in airstream. Found some vibration from blower motor. Bearings sound ok. Blower wheel was dirty and this may cause some pitch vibration. Cleaned the wheel as best I could. Without higher end electronic air filtration, this dirt will return. System was very dirty. Recommend yearly maintenance to ensure best chance for longer efficient lifespan of unit. System operating normal at this time. Job complete.