Furnace safety inspection. Cycled system. Checked heat exchanger. Found both chambers very rusted and worn. Found deep etching in both. Igniter worn and flame sensor is worn. Found exhaust venting not glued in two places. One near the termination, the other from the ventor motor. Both venting pipes were glued and checked, ok, Found the ventor motor very worn. Bearings are bad in motor. Checked levels of CO and XS air in exhaust. CO is normal, but XS air is high. 170. Found large area of rust in blower compartment. Cleared drain lines. Rust damage may be due to location in basement and leaking water issues from foundation. No CO found in airstream. System is 16 years old. Average life of this unit is 14 years. System is very worn and has issues, but operating safety at this time. Future failure is expected, but passes current inspection guidelines. Job complete.