has anyone seen any improvement in there tacoma with these? or is it a waste of money? ive been thinking of getting one (TRD preffered) but dont want to waste my money on something that does not work.

I don't have experience with them. What do the sellers claim they will do? Do they have any test data done by an independant test facility showing before and after results? What I have read only lists the sellers claims, they do say they look nice in the engine bay. I did see one site that mentioned voltage change improvement of a few millivolts, not enough to be help anything. Keep in mind the automotive computer operates on a small voltage, around 5 volts. They have their own voltage controls. probably a diode of some type that keeps the voltage at a steady 5 volts.

Clifton