So Last year I got a 2003 G35 Coupe 6mt with the Brembo Package. The car was good to me and all had about 290k on the Engine when I started getting knocking on Cylinder 2 and 6 So I went about Getting a Swap with a motor with around 136k on it. after the Swap the motors been Acting funny Since the car wont let me go past anywhere from 2500rpms to 4000 and when I do try to the car jerks really hard and the check engine light Comes on. I went to the mechanic that did the swap for me and he just got all defensive so hes not gonna be any Help on solving this problem. Does anyone have any ideas? the check engine light doesn't stay on. I also recently got the CamShaft sensor Changed because the Car was throwing that code when I got it back. ( the mechanic claimed my VDC systems were broken but that wasn't the Case).

If you post which diagnostic trouble code the vehicle is throwing then we can suggest ways to troubleshoot the problem.

They look like this for example.

P0340

I had a P0335 code which was solved and when I did try to rev past 4000 in neutral the same code came back but then went away

Also I know the mechanic had to finesse the sensor to get it to read properly he said something about where the sensor sits is warped or the flywheel isent on properly