Performed first year furnace cleaning; started by inspecting the exhaust and intake pvc ensuring all connections were glued, next I cleared out some blockage from drain line, I replaced 16x25x1 filter, next I removed and cleaned burners along with the flame sensor, then i cycled the system on to check gas pressures found 1st stage at 2.9 Inwc and found second stage cutting off as soon as it would engage. I adjusted 1st back down to 1.9inwc, and found a loose wire going to a pressure switch. Lastly performed a combustion test verifying no CO in the air stream. This sytem is currently operating normal at this time job complete