what is the best way to improve fuel economy and hp on 2002 f150 4.6L

I'm pretty new to automotive work but it is very interesting to me and since i began a new job i have done a fair bit of mechanicin'. I would like to do some work to my 2002 f150 it has a 4.6L V8 and i was wondering what is a good way to improve fuel efficiency and power. I would really like to keep my budget as low as possible but any advice would be great. Oh and please keep in mind that I need to pass a texas state inspection. Im not sure what they test in those inspections(maybe just emissions) but anything that i do needs to keep my truck passable. Thanks for any advice.

Milage! Every one is try to improve upon it. The hash reality is that on an 02 and newer the computer does such a good job computing the amount of fuel needed by controling timing, injector pulse and such that, as long as you keep up with your maintenance shcedule, you will get the best milage. Also driving habits play a HUGE part to how much gas you burn, as the truck "learns" how you drive and adapts everything to it. Run good oil ( motorcraft) and run ONLY motorcraft plugs. I have seen too many times were after market plugs have caused poor running and even miss fire codes.

Lower the weight of your truck as well, don't haul anything in the bed that doesn't need to be there, remove anything you have behind the seat that doesn't need to be there as well, every extra pound of weight the truck is carrying will lower your MPG.

Not much you can really do to a computer controlled engine to make it run better, keep up with the maintenance (oil, plugs, filters, etc.) and if you have a lead foot you need to turn it into aluminum or your MPG will greatly suffer.

there are things that you can do to improve your mileage and hp but they are costly and will pay for themselves in the long run. First thing to do is put a high flow air filter in your vehicle like a k&n air filter and it should improve your mileage about 1-2 mpg trust me I had a F150 with the 4.6 and it helped mine. The next thing you can do is put a superchips tuner in and it will pick up your hp 10-15 hp and your fuel mileage should increase about another 2 mpg. together you are looking about 600.00 but it will be worth it in the long run.

Watch your driving habits. For example, try to anticipate your stops from as far of a distance as you can so you coast for a farther distance before you apply the brakes. Also, accelerate slowlyand drive slower. You don't want to drive so slow you tick off other drivers. So what I do is always drive 5 mph slower than the speed limit unless it's under 45. I am feeling the crunch now with the gas prices, just as we all are, and have tried these techniques and saw a huge difference...went from 11 mpg to 18 mpg.

Turbo systems can increase gas mileage compared to stock mpg numbers because they make the engine more efficient and don't take power from the engine to make power. with a turbo you do not need a muffler. a dummy muffler would pass inspetion with a turbo.
Sct full engine parameter programmer is byfar the best ive seen. the engine parameters are not set to get great mileage and hp from the factory. don't go with k&n, have you ever noticed the oil on the filter? that oil comes off and gets on the maf and ait sensors causing them to work improperly, I found this out first hand. you can clean your maf and ait sensor tips with contact cleaner and a q-tip. carefull there easy to break. Pulse Plugs And high performance coils help a bunch. accell offers an coil w/10-15% more spark energy @ $24 each from jegs.com