My 2007 was chugging around 45 mph. I read the forums on here and decided to change my spark plugs. After changing them, it ran like a new truck. About a month later it is chugging again. I wouldn't think the plugs would go bad after a month. I am not getting any codes pop and when I am at higher speeds, if I put the gas pedal down, it surges a little as it is trying to accelerate until the engine rpm gets really high. I hate to go through and change the plugs but I don't know what else to look at. Does anyone have any suggestions please.

 

What kind of plugs did you use? Did you put in new COP boots and springs and use any dielectric grease?

 

I used the automate revolution HT plugs. I did not replace the COP boots because I did not read anything on replacing them. So to replace them, do they just pop off the old coil packs?

 

Yes they just pull off. Inside of the boot there is a spring. Replace that too. When you take the spring off take some fine sandpaper and clean off the terminal that the spring connects to.

And many like to stick with MC plugs, including myself.

 

Agreed, motorcraft sp515 and good point about cleaning the terminal off.

 

Typical Airframer installing wrong parts... do it correctly as stated above..

 

Plugs, coils, or injectors would be my guess. Mine did the same thing till I replaced the injectors. How many miles?

 

While you're at it, might as well clean the throttle body and MAF sensor. This can cause rough running as well. Never hurts!

 

All regular maintenance items...