I have a 2000 Lumina, 3.1L, I changed plugs and wires and the next day my light came on, computer reads a "P1381C Misfire Detected-No EBTCM/PCM Serial Data" code. If I clear the code out it might go away for a day or two and run great, and then all of a sudden the engine starts missing and within a few seconds the light comes back on.

What does this code mean? Do I have a brake control module going bad, loose wire somewhere, what should I look for? This just happened after changing plugs and wires, did I knock a cable loose somewhere that I can't find??? Any help is greatly appreciated on this.

Sounds like a loose/corroded battery cable or PCM ground problem to me.