Ford Repair: engine problem, sparkplugs, economical solution

Question
my 01 escape drove fine with occasional sluggishness yr prior a misfire or two and then went away...recently began again...check eng light came on stating sparkplugs, vac leak etc poss..so i changed spark plugs literally next day car went into limp mode.[.after many tests local mechanic] found water pump leak and bad catylytic converter in front manifold...still same problem..2-3 misfires and no powe in cylinder 4-6  took engine apart and had heads tested in local machine shop all testing fine and no leaks etc..still same result weeks later and about 1400 spent..towed to local dealer and tested, said low compression on cylineders4-6 and pistons bad resulting in need to replace engine.. please help is there any less costly way to repair these pistons rather than replace whole engine...spent way more than value of vehicle and still owe 5000 on loan...spent 1400 and will cost 2-3000 to replace engine!! please help with advice on what to do...   machine shop said tested fine but asking dealer stated that pistons or block would have to be removed and ind tested and this was prob not done....however hoping for alternative more economical solution? help thanks

Answer
Dear Denise, have anyone checked the coils.  Based on your descriptions, the coils might do the trick.  I don't think you need to change the engine.  An older car will some low compression due to the age of the engine.  Let me know how things works out...