I have a sudden loss of power, feels like I lost 75hp. No check engine (apart from the evap code that is always there). Power loss is more noticeable at higher rpms. No smoke, no noises, runs smoothly, starts no problem, oil is good (No flakes, foam, etc.), no signs of blow by etc. In Neutral it doesn't easily reach the limiter, it wouldn't even go past 4200 at one point ( sounded like it was bouncing off the limiter at 4200). After the full tank (noted Below) It will get to the limiter kinda weakly.
I figured I might have gotten some water in the gas a few weekends ago doing a deep river crossing. The tank finally got down to below a quarter full and I figured it was probably sucking some water. So I added some water remover and put in a full tank, its a bit better but not nearly where it should be power wise.
What are come common things to check out? Engine is a 4.6 stroker (All same accessory's etc. as 4.0)
To me it might still be a fuel issue? Maybe a clogged cat? Any pointers on what to check is appreciated.