ok so i have this annoying problem with my p5 it surges under moderate to hard acceleration also sometimes notice it on decel.I have been trying to fix this problem since i bought the car back in feb. i have no cel light no codes now does not backfire under decel. No misfire. What has been done so far is intake manifold gasket replaced, mass air flow cleaned, egr cleaned, iac cleaned, exhaust manifold gasket replaced, 1.8 coil conversion so coils replaced, throttle body cleaned, injectors replaced, fuel pressure regulator solenoid replaced ,plugs replaced ,wires replaced, intake hose thoroughly inspected for leaks and cracks and is in great shape. vaccum lines checked. i am out of ideas. can anyone help?

 

Have you tested the throttle body position sensor?
Have you tested the fuel pressure?

 

no have not tested tps as i dont know how and i was gonna test the fuel pressure but there is no fitting to hook uo the gauge im guessing it goes inline somewhere and i looked at the fsm and saw there little illistration but it was not clear as to where they hooked it up

 

There are several videos on Youtube on TPS testing. I.E.: and this should help with the fuel pressure:
Good luck to you!

 

thats was actually kinda usefull i dunno y i didnt think of youtube thanks... im leaning towards fuel pump still didnt test it yet but will soon