bigblue95z

There is a battery maintenance thing in the user manual that cured my hunting idle. I cleaned EVERYTHING and the writeup in the manual cleared up my idle issue. You disconnect the battery, let it idle with no A/C for 2-3 min, let it idle with A/C on for 2-3 min, then go for a 10+ mile drive. I've only seen like one person recommend doing this but I gave it a whirl I was so fed up and sure enough, it fixed it! Read up in the manual.

FordService

Hi everyone,

To add to what bigblue95z said, here are the tips from the owner's manual:

Because your vehicle’s engine is electronically controlled by a computer, some control conditions are maintained by power from the battery. When the battery is disconnected or a new battery is installed, the engine must relearn its idle and fuel trim strategy for optimum driveability and performance. To begin this process:

1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park) (automatic transmission) or the neutral position (manual transmission), turn off all accessories and start the engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.

• The vehicle may need to be driven 10 miles (16 km) or more to relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle quality of your vehicle may be adversely affected until the idle trim is eventually relearned.

~Natasha

kevinmalec

I was also experiencing lag/sluggish when accelarating. I mostly felt the lag in 2nd gear and going into 3rd. I cleaned my TB and the mass air sensor, but didn't feel much of a difference. However, once I changed my fuel filter it made a noticeable difference!