I have a 04 2wd Screw, with a a 4.6. It has 29,144 miles. I purchased it from an old man who is my neighbor and was the original owner. Today I finally got around to cleaning the M.A.F. and THROTTLE BODY. I took the throttle body off and boy was it BLACK and DIRTY. I was not expecting to see that kind of grim. Anyways I cleaned it to like shinny new and the M.A.F. too. How will this improve gas milage if any? Thanks.

 

What kind of mileage were you getting prior to the cleaning ? Properly metered air passing through a nice clean Throttle body can't be bad..

 

I was getting anywhere from 11.9 to 12.4 miles to a gallon. BUT my dual exhaust had a bad muffler. There was no muffler, just a shell, the guts were all rotted out making it hollow. I just replaced it last week with a new single 3" with a flow master 50 series. I do notice a better acceleration now with the back pressure. And after cleaning the M.A.F. and Throttle Body you can't even tell the motor is running its so smooth.

 

You might get a mile or possibly two IMHO, but don't expect any major leaps and bounds.

 

My 5.4 3v gets a lot better and I carry a lot in my bed constantly . I would expect a 4.6 to get 15 or so .I have 178k so yours should be better. Of course I never had a 4.6 . Maybe some true 4.6 guys will straighten me out .

 

My 5.4 gets better too.. and I run 35's

 

13 YO truck..
I'd do a tune up

 

There is no such thing as a 'tune up' anymore. Tune up means adjust the points/dwell/idle/carb mixture/jets to compensate for the mechanical wear. It's gotta be done like every 5-10k (Yes, I have several 40's era vehicles).

Now a days the ECU monitors everything and other than plugs (which most can go 100k now) there is no such thing as a tune up.... just standard inspect/replace (no adjustments).

yes, people can incorrectly say 'tune up' but it does not mean what they think it means.

 

Alright.
I know how modern vehicles work. Don't have 205k on my truck for no reason. I do appreciate the history lesson, but I'm pretty sure he knows remotely what I was talking about and it's nothing a simple question couldn't have resolved...but I digress.

 

I do realize that I need to change my plugs. They are factory origin also and 13 years old. Just afraid to do them with the horror stories of them breaking, and shooting jut of the threads.