Are they worth it

I heard about these "Power Modules" that give you 15hp is this BS or real

Also what about the Pulleys are they worth it some claim 20hp

Power modules are crap, pulleys work tho

well if you mean a hypertec style tuner, or a custom burned PROM chip when you say power module, then yes, they do work, if you are talking about the little resistor that plugs into the IAT sensor plug, then no, save your money. and yes, the power pullies do work, although sometimes they create chargine problems.

15 and 20 horsepower might be a stretch but they work fairly well...