I have a 1999 F-150 with the 5.4 engine. I have been considering getting the Hypertech Power Programmer III to re-program the computer. Also, I have been looking at the Gibson Side Swept cat back exhaust system. Do any of you guys have any input on these ideas? The programmers have been going for around $200 - $250 on E-bay, is it worth it? Would it be a good idea to buy one, reprogram the truck, then sell it? Why would you ever need to un-program it again?