Some 2008-2010 Ford F-Super-Duty vehicles equipped with the 5.4L engine may exhibit a MIL on with DTC P2135. Various other DTCs may also be present. Drivability symptoms may include intermittent rough idle, idle speed below specification and/or reduced power.
The concern may be attributed to throttle position sensor (TPS) hardware. Follow the steps in the service manual section 303-14A to replace the TPS.
Use new TPS P/N 6L2Z-9B989-D.