Ignition miss or what?
#11
I worked on a gm product, granted it's a gm. But the same 5v wire supplied everything from the O2 sensors, to the maf sensor, and everything else. Chased my **** for a week, finally found a shorted O2 sensor internally it shorted out back feeding the 5v system, caused all kinds of problems. Very similar to the PO in this thread.