Question

2001 Doge 1500 V8 the engine has an intermittent misfire, pops back through the intake when this happens, cel on now with p0172 hard fault

Answer 1

Hi there,

The misfire could be causing the rich fuel mix code. I would try to isolate the misfire by when the condition happens, unplug one coil at a time on that bank. If the engine misses worse, plug it back in and go for the next one. Eventually you will find the cylinder that has the issue. Then try to diagnose why from there.