Furnace clean and tune. Cycled system. Checked heat exchanger. Found all chambers very rusted, but no cracks found at this time. Checked and cleaned burners and flame sensor, ok. Found igniter very worn. Igniter tested a little low, but in ok range at this time. Checked gas pressures and adjusted to maximize efficiency. Checked for CO and XS air levels in exhaust. Normal levels of both found. No CO found in airstream. System is worn, but operating normal at this time. Ac safety inspection. Used refrigerant sniffer on indoor coil. Possible indications of small leak. Cycled ac unit. Checked pressures and temps. Found refrigerant level to be a little low, but in range at this time. Checked compressor. Tested compressor with megometer. System is testing ok. Capacitor is low, but tested in normal range at this time. Split was 16. System is worn, but operating normal at this time. Job complete.