Joined: Sat Jan 13th, 2018
Interests: cars, trucks, running
Reputation Points: 1044
|If put fresh plugs in, and dont idle it, go for a drive, steady state, shut it down and pull them again, they'll tell a good tale. But if your mpg's are fine, I'd suspect you don't have an issue.
IF you have forscan or a similar software you can monitor fuel trims and see if the truck is commanding to much fuel.
The only sure fire way though is to install a wideband.
2001 Ford Lightning - Built Motor - Built Trans - 2.9 Whipple - E85 - Custom Interior - 537/632 - 11.40 @ 119.6(old setup)
1968 Ford Mustang "Gold Nugget Special"
2018 Ford Mustang GT PP1