97 f-150 4.6L, heres the deal. i just got the truck last week, its been sitting outside in the rain for about a year with broken front passenger & driver rear ext cab window. it ran fine but needed brake work when parked(windows busted after having been parked).

When i first tryed to start it, it would only fire with help of starter fluid. Once it started i ran much of old gas out of the gas tank without completely running it dry(to avoid possible trash blockage), although it did not run pretty, spark knock and missing badly. Put new gas and gas treatment in. Ran that tank out, added new gas. replaced plugs & wires-no change, replaced both coil packs-better due to crack in one coil pack, but still missing bad.

Started to clean out the EGR valve but first bolt broke off so i left it alone untill i seeked better diagnostic testing. This is where i turn to your help. A friend told me that he had similar problems and a new computer solved his problems. Also told me he had to have a dealership program it.

The check engine light is NOT on either. Have heard that codes will not show up without check engine light registering?

Any idea on cost of new computer? I can install myself, but not sure what to do about having it programed or how much $$$.

If i take it to a shop with a computer diagnostic tester with problem show up?

Thankx for any help, im not that firmiliar with newer trucks/trobleshooting.