flashing 12 is normal, that code is always there. what sort of shape is the harmonic balancer in? possible your TDC mark has moved. you set timing to 0* with the ESC wire unplugged right?Well timing was okay but I don’t know how to explain it haha. The mark was so far retar*ed when the 5.0 stuff was hooked up. But anyways, ran, but then I unplugged the map sensor and it shut the truck off as it should. Put all the original sensors back on…. And now she cranks but no start hahaha. This engine is a nightmare. My money is on the ECU. I was able to get power to my obd port… just kept flashing 12. I know that means no issues, but it wouldn’t change. Stayed flashing 12 and the service light is on still as well.