With this job, I was performing your routine maintenance on an air conditioner and furnace. Upon checking the furnace everything checked out well however static pressure was a bit high. I believe some of this is due to the fact that the coil and the furnace are not built for each other. And the return drop on the system could be a little bit bigger. These are things that I would bring up when it comes time to replace either part of the system.the outdoor condensing unit all refrigerant levels are good and all electrical components operating well within manufacture specifications. I washed out the unit and changed the filter and everything is running well at this time. In the future, I would look at duct cleaning because the air ducts are quite dirty.