cars still loosing power starting around 3500rpm

[fordgasm]

You need to have a fuel pressure gauge so that you can see what pressure you are holding. Preferably one that you can read while you are driving to see if the pressure drops as the rpm increases.

The regulators can fail also, they have a rubber diaphram in them that can develope a leak. With a fuel pressure guage you can see if the fuel system is holding pressure or not.

Do you have an aftermarket adjustable regulator or the stock one? Do you have a fuel pressure gauge?

What about your fuel pump? Is it original equipment? There is not all that much with the fuel system. You have the fuel pump, the fuel filter, the fuel regulator and the injectors. I would try to eliminate each item one at a time, starting at the least expensive.

Your type of problem is usually going to be either electrical or fuel related and it sounds like you have already addressed all the electrical items. I would now focus on the fuel system. It is very difficult to diagnose your problems over the internet, but from what you have described this is the approach I would take.

What year is your car and how many miles are on it? What is the general condition of the car?

Just because a cat is not glowing does not mean it is fine, they can have a restriction and not glow, but may be hotter than normal. Too bad your not closer, I have a brand new factory H pipe with the 4 cats on it that I took off in 1990 after a Ford recall. My local Ford dealer put the new H pipe on then I took it home and put a set of long tubes and off road H pipe on. They have been sitting in the rafters of my garage for years. If you were a local guy I would let you install them, but if you were a local guy you would probably go with an offroad H pipe

Hope that helps, just address each item one at a time and only make one change at a time so that you know where you are at.