I read that if the Injector O-rings are leaking you will find oil in the fuel bowl. Is that always the case? I recall reading somewhere that it depends on which o-rings are leaking. I just checked my fuel bowl and no evidence of oil whatsoever.
The reason I suspect o-rings is I get P1211 code very consistently when under acceleration for longer than 7 seconds. Pulled ICP/IPR readings and was getting IPR of 54%, yet ICP was only 2500 PSI. Once it triggers CEL, IRP goes down to around 30% and truck loses perhaps 20% power. Have recently cleaned IPR, and since it is very consistent, was guessing it is not IPR. Also, when I checked oil level, I was down 3 quarts, with no evidence of such in the driveway.