Originally Posted by 370zFORme!!
Never! I dont even shop at costco let alone use their gas.
I have always used 91. There is a gas station near my parents that sells race gas 100 octane! I might try that and see if that helps!
I am going to recommend this before Modshack does...run a bottle Techron Concentrate Plus
in your gas tank and see what that does. Also, what vehicle did you have before this as injectors can be very noisy at times and if you are not accustom to the noise then the first time you deal with it is always appears odd.