I'm upgrading my 98 F-150 from a 4.6 to a 5.4 everything is going good so far but i'm stuck on the knock sensor. The 5.4 is different from the 4.6. the plug end on wire harness is the same plug end thats on the new sensor except there are three wires on the sensor and two on the harness. So i bought a new pigtail for the sensor from ford but again the harness only has two wires what do i do now?!! if anyone has come against this please let me know what you did... Thanks in advance!!

 

Have you read the swap notes? Maybe it sais in there. I'm not to familiar, but I thought you had to use the 4.6 harness and coil packs during a 4.6 to 5.4 swap, but maybe I am wrong.

https://www.f150online.com/forums/ar...ml#post3570245

Wait, which engine harness are you using? the 4.6 or 5.4

Heres what it sais in the swap notes

Knock Sensor: The 97-98 99 4.6 uses a 2 wire knock sensor. The 97-98 5.4 has 3 wires of which one is a ground for the shield. Both have a Yellow /red wire to pin 57 on PCM.
1997-98-99-2000-01 Yellow/red to 57 on PCM 4.6 Same for 5.4.
97-98 Pin 91 feeds power for 4.6 and other components. Same for 5.4
1999- 2000-01 Pin 32 for power. Same for 5.4
2002+ Cannot confirm.

So it sounds like your using the 4.6 harness with the 2 wire knock sensor? And the knock sensor in the 5.4 engine has a 3 wire..

 

You can cancel out one of the wires. When I did my swap I followed the swap notes and it has been working fine for me. I just cut the end of the harness from the 4.6 knock sensor and spliced that with two of wires from the 5.4 knock sensor. Seems like the 5.4 has a hot / ground and neutral. I can't remember off the top of my head which one to cancel but look up the swap notes and you should find it.