i have been change the motor of my alfa 147 1.6 eco to 2.0 . but start so much problem . i didnt change the ecu , the motor is working but is more weak than it should be and more weak than 1.6 .the rpm dont exceed 4500 rpm. i change the manifold of the exhaust and the mass air flow sensor and it become better alittle but still weak for 1.6 .. i need help . i wonder if have solution without change the ecu ..