318is 1.9M44 1998

Hey guys hope someone can shed some light here. The problem is at full throttle when the engine is warm it hesitates and won't pull. If I back the pedal off about 1inch it pulls fine but that last inch of pedal makes it hesitate. When the engine is cold it's fine as soon as it warms up it starts. Things I've done. Replaced MAF, throttle position sensor, idle valve (just in case). Fuel filter. Replaced vacuum pipes on the injectors, cam sensor, gaskets on intake manifold, checked for leaks etc etc. Couple of things to note. Diagnostics shows a fuel pump relay fault. Changed it. Live data on the diagnostics shows that the throttle position sensor maxes out at 67% @ full pedal press is this normal? The old one said the same.... I work as a mechanic (I'm by no means the best) so I'm not totally daft lol but this has got me baffled! Only other thing to note the ECU was re mapped before I bought it could it be a dicky map? I have a spare ECU is it a plug n play thing to try it or will it need coded etc. Thanks guys any help would be greatly appreciated.