Complete heating tune up inspection special in Stone Mountain. Check and find 17 year old Rheem gas furnace in crawlspace. Find furnace operating with high temperature due to incomplete combustion and high gas pressure, gas line not code and flue pipe code. Find furnace operating with weak flame sensor and baldy worn ignition. System very dirty, blower assembly and motor dirty. Find ac unit have no pipe insulation, and missing cap. Due to system age and conditions, suggest to upgrade system.