u/Dense-Expert7087

Attached picture is full throttle

2006 f250, 4x4, 355k miles (ain’t even broken in yet). I’ve had quite a few of these trucks now, but this one is stumping me.

Background Info: fully bulletproofed and deleted besides for still having the cat on. Transmission was rebuilt at 190k, along with head gaskets, oil cooler, studded, stock injectors rebuild with WDI spools and 155cc nozzles.

Just picked it up from down south for cheap, knowing it had a high pressure oil leak but still ran and would start hot with starting fluid. I replaced the dummy plugs and stand pipes with oems, and the top injector seals. I also replaced the glow plug module and that removed the check engine light for that.

But it seems to drive good if not fast when on flat roads, with no load, and can get up past 100. However uphill if I’m going 60 I need to floor it to maintain 60. Likewise while pulling a small to medium size load uphill. It’s a little slower on flat while towing as well.

It has an sct tuner, I have gone between street tune and stock tune. Under full throttle, ipr hits 80 (not 85), icp is at 4k (online it says that this is adequate). But if I’m really beating on it at full throttle, sometimes the rpm’s will go from their normal 3-3500 ish to like 4-4500 ish in a little flicker of power. So I believe that’s the power that this truck is supposed to have, but it seems something is bottlenecking it.

It threw codes for P2285 P2287 when the rpm flickering happens. (ICP sensor circuit low / fault, ICP sensor intermittent / erratic)

I am somewhat stumped though, as the icp voltage does not appear to be erratic. I replaced the fuel filters, which were very very dirty, but did not notice a difference in power under load.

The only thing left in my mind is to remove the cat and see how it drives, and remove the air filter to see if it’s causing a restriction but the air filter appears pretty new (oem style).

If anyone has any theories or things to check, please let me know.