2004 F-150 FX4
4" lift
35" tires
Volant CAI
SI SO Flowmaster muffler
68K miles

In the last 5k miles I have noticed my acceleration really decreasing. I have a heavy foot once and awhile, like sometimes I like to stomp on it at a green light. Or when I pull out in traffic and really step on it. Just not seeing the same response lately! Dont get me wrong it still has ***** but not as big as they use to be. I understand I cant expect the same throttle response as when I bought it with 25k miles. But come on when I got beat by an older chevy s10 pickup with some loud crappy exhaust the other day it defiantly made me wonder. I use to have no problem beating other trucks.
About 5k miles ago I cleaned my MAF, the Throttle body, and changed fluid in my rear diff. to full syn. I sprayed the maf with electrical connection cleaner and cleaned out the throttle body cylinder. I keep my air filter pretty clean, I clean it about every oil change. Could i have screwed something up? What is some advice on my next step to replace, check, re-clean, or replace.

 

Well, the lift and tires slowya down a bit... but what will really get her up and running is a custom tune. I recommend getting a Gryphon or SCT Livewire with some customs. Look to spend 500 bucks for them.

 

Get some 4.56 gears and you will see your truck back to normal before you know it. I also agree 100% with the Gryphon custom tune.

 

Yes I am going get that gryphon tuner with the special tunes, I am just saving up for it.

The 4:56 gear- I had a Ford Ranger with those gears and yes I will have great take off but will it hurt my MPG or Highway driving?

But what about my MAF sensor could I have tweaked some setting by spraying maybe to much or in the wrong area?

 

I would not go any higher than 3.73 is you are worried about MPGs.
3.55 do well for my truck as I do not tow that often, maybe a friends broken down car once a year...

And yes, if you sprayed inside the sensor, you will be screwed.... but I highly doubt you did that.

 

I didnt open up the MAF sensor, I just unscrewed it from my CAI tube that goes to my THrottle body. I am going take a pic of it tomorrow morning and post it. Maybe there is a part of it that your not suppose to spray clean.

And I am not going change my gears, Thats not real high on my modifications I wanna do to my truck. First will be the gryphon tuner.

 

ok so I didnt take a pic of mine but this one is just like it. I sprayed it with cleaner in every crack and opening but didnt open it up. SHould have not sprayed the cleaner inside the little slots?

 

I would not have sprayed the sensor itself, the electrical connector cleaner is only to clean and protect the connection. If you're concerned about it, change it and the good thing is MAF's are a cheap, easy part to replace; try it and see if you there is any improvement

 

Umm if he is running 35" tires that is putting way to much strain on 3.73s. He needs at a very minimum 4.10s to keep everything balanced and get his truck back to normal. Then he needs a programmer to tune his PCM to basically tell it his new gear ratio and tire size.

 

Not a very wise decision.