I noticed that when in VTEC I have a nice big cloud of black smoke coming from the exhaust now this is not normal VTEC smoke this is 89 ford pickup truck smoke now I could only think of a few reasons for this: A. My O2 sensors are bad. or B. my old ass wires are not burning the fule to its fullest. what else could it be the fuel pressure has never been messed with. keep in mind I recently installed my header and the O2 sensor for cyl. 1-2 are on the primaries O2 sensor for 3-4 sits on the collector could this change in O2 location have caused this?