I was getting this code right after I had the HPFP recall done as well. Could not find a definite answer in what it was, but since it comes up as "Fuel Quantity Lower than Expected", I took a guess and replaced the upstream O2 sensor (P/N 68171190AC). Code hasn't come back since.
I am surprised at your resolution. When I received this code my system diagnostic algorithm ended up with the fuel tank lift pump not supplying sufficient volume. When I experience this code again I will have to look into the O2 readings.
RCD is selling a modified CP4 ..I just bought one, it looks like a good option to those like me who are looking to bulletproof the eco.
I cannopt use a dealer as my gen 3 swap into a gen 2 chassis would mark me as a bad actor...
Sooooo the CPX replacement looks likle my best bet.
