Sp 542

[Jake17]

Nothin' wrong with the factory plugs.

 

[Roger33]

I have a 2018 that has 600 miles on it and I thought that the ignition was breaking down under hard acceleration and figured that I would give it time.....I am impatient so I installed the 542'2 in my truck yesterday and the issues are completely gone. I am n California and I am wondering if the trucks that seem to all have these issues with the hotter plugs are based on the West Coast....could be a California Emission requirement to run those plugs. In any case, the colder plugs resolved my issues.

 

[Umlify]

What’s the consensus on the proper gap when switching to these SP 542 plugs?

 

[Roger33]

What’s the consensus on the proper gap when switching to these SP 542 plugs?

The gap on the plugs I installed was .030

 

[Quiker]

I just ordered SP-542 - received SP-578 - called the dealer - sure enough they tell me 578 superseded 542..... anyone else find this out?

 

[TXRaptor]

This thread was from a year ago, so it is possible the new plugs supersede the 542s I have installed in my truck.

Please report back if you find out for sure.

 

[tlnt60]

This thread was from a year ago, so it is possible the new plugs supersede the 542s I have installed in my truck.

Please report back if you find out for sure.

the new plugs for sure supersede the 542s. I verified with ford and 3rd party. I will install this weekend and see how it does. I have a 17btw

 

[nikhsub1]

For anyone looking for sp-542's, I don't believe the 578's are the same as the 542. I think that part number M-12405-35T is the equivalent to the old sp-542.

 

[nikhsub1]

I have now 100% verified this, the 578 IS NOT THE new 542 - the SP-578 is the new OEM plug, it is NOT as cold as the 542... see here:
https://www.fordraptorforum.com/threads/fyi-sp-542-successor-is-not-the-sp-578.75215/