My hwy mileage dropped to 16.3 from 19 so I had to look into it. Autoenginuity scan tool, no codes set in any of the 4 code families.
Scan tool has a MAP test function, tests 1 and 2. It failed test 1 yet no codes current or pending.
Replaced MAP (OEM replacement) and mpg came back to 19 hwy. on a 250 mile test run.
In my diagnosing I saw the real time mpg bouncing around on decel. from 99 mpg to down in the fifties and back up all over the place with foot off the gas. Zero drivability issues also.
Just sharing incase someone else runs into this.
Scan tool has a MAP test function, tests 1 and 2. It failed test 1 yet no codes current or pending.
Replaced MAP (OEM replacement) and mpg came back to 19 hwy. on a 250 mile test run.
In my diagnosing I saw the real time mpg bouncing around on decel. from 99 mpg to down in the fifties and back up all over the place with foot off the gas. Zero drivability issues also.
Just sharing incase someone else runs into this.