P1117 - can't clear code

[Zzorro]

Got another 100kms from driving yesterday. 50 kms to work and back. On the way back home I didn't get a CEL but I did get a recurrence of an issue if have been trying to chase down.

The car will "stumble" or loose all power at higher revs. It will just bog right down under load. It feels like it's not getting fuel, but when I take my foot off the gas it returns to idle just fine and does not stall.

To remedy this, I shut off the car and restart it. After the restart it works fine again like nothin happened. During previous occurrences it would sort of stumble along for a min and then return to normal, be like nothing happened. But I just restart now. This happens very infrequently. Maybe once every 800kms to 1000kms? Sometimes I get a CEL and sometimes I don't.

To address this issue specifically I have replaced the fuel pump. Then I did the coils and plugs and all O2 sensors. Plus earlier I replaced MAF. Apart from the fuel pump, the latter items are all related to clearing codes and needed to be done anyways. (So I'm not throwing parts at the car for this issue specifically). But thought that getting some of these parts would take care of this issue.

Anyways, because the issue is so intermittent, I'm asking if checking fuel pressure or injectors will even help? Could this be something to do with the ECU itself maybe?