Noticed really poor mileage around town lately dropping from around 17 mpg to 15 mpg. So I reset the trip A computer and took the Pilot out on the highway for an Italian tune up. Mileage went from an average of 15.3 mpg over the past 1702.9 mostly local miles to 26.2 mpg on a short 18.3 mile test ride on the highway. As soon as I got back on city streets the mileage started rapidly dropping. In another 6 miles the average including the high highway mileage had dropped to 16 mpg. I recently changed plugs, cleaned the MAF, and replaced the PCV and EGR valves. Checked for dragging brakes, wheel bearings, tire pressure, all fluid levels. No clue why local is so low and highway mileage remains excellent. I realize the trip computer isn’t all that accurate but a 15/26 city/highway spread is extraordinary. Any ideas?