This a JDM vg30dett engine i went to replace the knock sensor and got lazy and only took the idler pully off to raise the lower plenum every thing was replaced and put back first question is was i suppose to set the car a TDC ? when i went to start the car would not fire just made a wierd sound i checked for codes and came up with 21 PTU bought a new one never tryed installing and fireing yet second question is what would be damaged do to this and also does timing have to be rest