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.

 

Sounds like one of the other 5 coils is going bad. Your check engine light will come on soon and reveal what cylinder it is. I worked on a 01 last week that was doing the same thing and the light finally came on showed a misfire code.

 

Thank's Torkum,

I'll take it back by after the New Year to see if I get any codes. Does the analyzer that Auto-zone uses catch all of the fail codes? I know the guys at the Ford shop hook up a laptop and seem to get alot more info. They charge $65.00 for diagnostic fee. Should I trust the Auto-zone codes, or is the 65 money well spent?

 

Have heard torkum say the computor is slow to catch COP codes. Am not the guru on the subject. He is a pretty straight shooter.

 

AutoZone uses a code reader that will only read pending codes and fault codes. A true scanner will read [mode6] misfire monitors that will show each cylinders activity.
I would still give it a few more miles to set a code.

 

i know this happened awhile ago but was it the fuel filter? i may have the same problem and i had the filter changed (it was original) and it fixed the problem about 95% . let me know. Marc