Question

2011 Ford F350 with engine code P20E8, what does this mean?

Answer 1

There are two areas that cause this code to set the reductant pressure or the reductant pump. More than anything it would be the reductant pump that happens in many cases the fluid leaks internally into the pump which renders it to produce the low pressure.

P20E8 FORD - Reductant Pressure Too Low
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