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ok ive asked this once already but no answers but does the high flow cat random tech has thro cels or not? i already tried the resonator wit 2 different style cel eliminators and still cels every other day so i thru that away and bought a stock replacement 4 now. that and i need 2 no if i need a extension for the down stream o2 sensor? and if any1 has any hp gains mayb? ive got 115whp so far and im reachn 4 120.