I was having a bad miss in my truck so i brought it to my friend a local mechanic. He put his scan tool on the truck and told me i was having a missfire in cylinder 7 so i went to the parts store got a coil and 8 ngk iridium plugs because they were $6.50 a pop i couldnt pass em up. So i run some sea foam through the fuel and air system and do my tune up....the plugs i pulled out looked really really raunchy and rust covered...aswell as the boots of the coils so i took the boots off and sanded the rust off the slinky things inside the boots. i added dialetric to all of them and the boots. Well once i got done after breaking a fuel injector and having to wait on that for a day i get the truck and take it for a test drive...

Now here is the kicker i have never i mean never been able to power brake this truck its a 5.4l Supercrew f150 w/ tlok factory. By the way i bought the truck with 40k on the odometer, and now on dry pavement it effortlessly powerbrakes...is this right can replacing old plugs really bring a truck back to life like this or am i on crack ?

Just sharing my experience but im glad to have my truck back to normal

 

Its probably more the apprpriately firing coil pack and cleaned connections than anything else, plus, remember its really cold outside right now (it is most places anyway) and that makes the rubber on your tires harder, and the air charge to the engine denser, which will make more power and easier traction breaking

 

You just didn't know how bad the original parts were.
Like the difference between worn out shocks and new ones.

 

Plugs do make a difference! So does new air filters!