it that time of the year and im due but im about 350% sure im not passing... im burning super rich and i tried everything to get rid of it but nothing seems to be working...new vacuums, new intake manifold gasket, sparks, wires, coolant flush, cover gasket, rewired knock sensor, no engine codes, except for a 51 but only when i rev it up a little.... anybody got any suggestions? what should i do next??