I have a 2007 f150 5.4 lariat 4x4 wanting to change plugs my question is which do I use the sp 515 plugs or the 546 or does it matter thanks guys

 

546

 

Sp546

 

x3 these are the latest updated version and least likely to break off at next change.

 

Thanks guys I knew they was the improved ones just wanted clarification before I bought them.

 

Make sure you change out the boots and springs too! Cheap insurance

 

How do I get to the back passenger side one I can't get to it to turn it with ratchet

 

You need to disconnect the battery and remove the ECM and the bracket.

 

You need to carefully unplug the PCM (3 cables) and remove it (4- 10mm bolts) and then remove its bracket (3- 10mm bolts). Press the red connectors firmly into the cables once unplugged to ensure they're seated. As an extra measure of caution, disconnect the negative battery cable. Ford says to complete the throttle body re-learn procedure whenever the battery/PCM is disconnected.

 

mite as well clean that Throttle body while you are at it...