So my truck says i am getting 10 mpg and has been for a while. Everything is stock except I made my own CAI and an E-fan but i put those in a while ago and it was helping and I upgraded to synthetic oil. It seems like it happened after i removed my throttle body to try and clean it it got worse and on top of that when I step on the gas pedal at a certain spot theres a high pitch squeeling noise which im assuming is from removing the throttle body. I dont know if theres a certain way i put i on without a good seal or something cause i removed it and tightened down the bolts as tight as i could but doesnt seem to help so i dont know if its from somewhere else. But main thing why only 10 mpg? Thank you for all your help!

 

First thought - have you changed tire size without getting the computer reprogrammed to compensate? If you went to a larger tire size, the speedometer and odometer are reading lower than your actual mileage and speed. This will give you an indicated lower MPG because the calculation will be based on the incorrect distance.

Another thought - with the "squealing" noise - could be a vacuum leak or an improperly attached throttle body or air intake pipe.

Does the truck feel like it's less powerful than in the past?

How many miles? Have you changed the plugs lately?

 

The tires are the stock tires and I re bolted the throttle body the same way it was before but I dont know if I have to put a new seal on it or what and i have high 40K on my truck and havent changed the plugs

 

What did you use to clean your throttle body?

 

Some random cleaner I found I couldnt tell you exactly. Could that screw it up?

 

The throttle body is electronic controlled, moister and electronics don't get along well with each other, so that might be your problem. Brake clean works best since it evaporates very fast, and always hold the TB with the electronics up so no fluid can run into it.

 

So if fluids did get in there what do I do now?

 

Do you know anyone around you that has a truck with a hemi? If so, see if you can borrow their TB and see if your truck runs better. If it does, then you need a new TB. I don't know if the electronics can be dried out or what.

 

Now I dont have a hemi and mine is a 4.7 could I use a 5.7 hemi on mine?

 

no different throttle body on the two models...

Some people have talked about putting a gasket on when taking it off, and I havent done it for that reason. Possible a vacuum/air leak