1999 F150 Sputtering
Drove 160 miles, heading to deer lease. Stopped and got gas in Atlanta Tx. Truck started sputtering when it went into overdrive, and going up hills for the last 12 miles of my drive. Went back into town the next day and the truck ran fine for 12 miles. Went to Auto-zone and they hooked up and showed no codes. Bought some fuel addative just in case I got bad gas. Left the following day to return home and truck started sputtering under load. Continued to get worse, and now sputtering can be detected even at idle. Recently replaced mass airflow sensor, plugs, and 3 coils. Check engine light has not come on. Any advise appreciated.