No power on acceleration, but idles perfectly, it actually loses power on partial throttle, extremely hard to accelerate

I disconnected the exhaust at the manifold and got the same response

5o psi

12 Volts at the fuel pump and I put a new one that came with a sending unit. It was a Delphi unit

Fuel Pump and Sending Unit, Delphi Manufacture, which I believe is OEM, I did not replace the fuel pressure regulator, or the MAF unit

Not to be a Knucklehead but what if it's not the fuel pressure regulator.The pressore port for teting the fuel press. was between the fan belt and I was a little hesitent to in getting a reading

I replaced the fuel pressure regulator and the engine still responds in the same manner.Poor throttle response, no power after partial throttle.

Once again, the vehicle came in with a check eng lite and complaint of no power on aceleration at half throttle. I scanned the diagnostics and it had an EGR code. I replace the EGR valve NAPA brand.Cleared the codes,started the engine no check engine lite. I went to road test and the vehicle still had no power. Idisconnected the exhaust at the manifold and still had no power. I replaced the fuel fiter, the fuel pump, the TPS switch and the fuel pressure regulator that you thought might be the problem. I also checked the plugs, took a compression check 135 psi on a hot engine. I checked coil packs for spark at high rpms, replaced air filter and cleaned throttle body. Now, I disconnected the EGR connector it had a little and I stress little more power but not much more then avery little. It's a struggle after 20mph. Any other possiblities????

Hello, I've been waiting for a reply and in the mean time I have trouble shoot it and it is on the EGR wirng I have voltage going in but nothing coming out