I have an 03 G35 coupe and i'm throwing a 0021 code. I have changed the oil, changed the ivt control solenoid, cam, and crank sensors. I'm still throwing the code, and don't know why. I have a built motor and the PE TT kit. The only thing i can think of it might be is i have a blown head gasket but don't know if that would even relate to my problem. Can anyone help me???

 

Try disconnecting your battery for at east 24-30hours. I read from other forms and appeared to have worked for them after checking/changing oil and restoring. I had this code pop up after changing my flywheel/clutch.

 

You can reset your EC just prior to reconnecting the battery by pressing the brake pedal twice for 5 seconds each time- this discharges any potential left-over current from the capacitors in the electrical system. There are quicker ways to reset the ECU, but I'll let someone else delve into that.

And yes, I think your blown head gasket has a direct connection to variable valve timing since the timing is ECU controlled, which uses input from a number of engine sensors- the oil control valve, the actuator, those sensors that measure airflow into the intake system, throttle position and camshaft position.... and... coolant temperature (which a blown head gasket will affect)!

Hope this helps!