Does anyone know if those 10-20 modchips they sell on ebay actually increase your horsepower? are they a good idea to get or worth it??

dont waste your money on them.. all the do is trick your map/maf etc to think that the car is running cooler than it actually is.. somewhere I have those instructions if I can find them I will post them for you so you can save some cash and do it yourself if your really interested

k so it does help?? and i can do it myself?

No it doesn't help. It can hurt your car in the long run!!!

my friend blew his motor with that crap.