How to Install K&N Series 77 High Flow Performance Cold Air Intake on your F-150

2. Release the red locking tab and then disconnect the mass air sensor electrical connection.

3. Release the green locking tab and then disconnect the crankcase vent line from the intake tube as shown. 

4. Loosen the hose clamp that secures the intake tube to the throttle body. 

5. Release the three retaining clips that secure the upper airbox to the lower airbox.

6. Remove the upper airbox housing and intake tube assembly from the vehicle.  

NOTE: K&N Engineering, Inc., recommends that customers do not discard factory air intake. 

7. Remove the air filter from the lower airbox.

8. Remove the center upper airbox retaining clip from the lower airbox. 

9. Install the K&N® filter adapter into the heat shield as shown. Secure with the provided hardware. 

10. Install the provided edge trim onto the heat shield as shown.  

NOTE: Some trimming of the edge trim will be necessary. 

11. Cut the 19” section of small edge trim into two 9-1/2 lengths. 

12. Install the two 9-1/2” lengths of small edge trim onto the heat shield as shown. 

13. Install the K&N® air filter onto the filter adapter and secure with the provided hose clamp. 

14. Install the provided silicone hose (08699) onto the filter adapter as shown. Secure with the provided hose clamp. 

15. Install the completed heat shield/filter assembly onto the lower airbox. Secure with the two factory airbox retaining clips.  

NOTE: A gap is normal between the lower airbox and the heat shield on the clip side of the heat shield. 

16. Install the provided silicone hose (08699) onto the throttle body and secure with the provided hose clamp. 

17. Remove the two screws securing the mass air sensor to the factory airbox, and then remove the mass air sensor. 

18. Install the mass air sensor into the K&N® intake tube as shown, secure with the provided hardware. 

19. Install the provided crankcase vent fitting into the K&N® intake tube as shown.  

NOTE: Plastic NPT fittings are easy to cross thread. Install the vent fitting “hand” tight, then turn it two complete turns with a wrench. 

20. Install the K&N® intake tube; insert the lower end into the silicone hose attached to the heat shield /air filter assembly. Attach the upper end of the intake tube to the silicone hose secured to the throttle body. Secure the intake tube with the provided hose clamps. 

21. Rotate the crankcase vent coupler so it lines up with the fitting installed into the K&N® intake tube; connect the coupler to the fitting. 

22. Connect the provided mass air sensor extension harness into the factory connector and then connect the open end to the mass air sensor electrical connection.  

NOTE: Be sure to lock the mass air sensor connections with the red tabs. 

23. Reconnect the vehicle’s negative battery cable. Double check to make sure everything is tight and properly positioned before starting the vehicle. 

24. The C.A.R.B. exemption sticker, (attached), must be visible under the hood so that an emissions inspector can see it when the vehicle is required to be tested for emissions. California requires testing every two years, other states may vary. 

25. It will be necessary for all K&N® high flow intake systems to be checked periodically for realignment, clearance and tightening of all connections. Failure to follow the above instructions or proper maintenance may void warranty.