i think norachelhere is right. i have worked in alot of part stores and have always told people to try those kind of things becuase the company would tell us to sell them but most people would come back and say they work rather well. i started using them and noticed a difference. the seafoam treatment works well too. i like to suck it up into a vacuum line that is not vital to running your car i try to find one closest to the throttle body