I have a 2005 G35 Coupe 6mt with a Service Engine Light on I got the code (P0340), which is to replace the camshaft position sensor (bank1). The car drives fine and have not had any mechanical problems with it (unlike some of the other threads I read about P0340).

Here's a list of things either myself or my mechanic have tried:
1.) Replaced bank 1 camshaft position sensor with one I bought at O'Reilly's
2.) Replaced bank 1 camshaft position sensor with OEM (part# 23731-6J90D) - Purchased from www.infinitiwholesaledirect.com
3.) Replaced Variable Valve Timing Solenoid (part# 23796-EG22A)
Replaced Solenoid Gasket (part# 23797-2Y50A)
Replaced Control Valve solenoid RT side (part # 23796-EA22A)

He resets the Service Engine Light each time - and light comes back on after about 5-10miles after driving. My mechanic says he can't find anything mechanically wrong with the car and is now suggesting that I bring it to the dealer for an ECM Flash. Does this seem reasonable? I've been looking at other posts on this topic and cant seem to find an answer.

Thanks

 

Called the dealership and they recommended trying to replace the crankshaft position sensor (23731-AL60E)

 

Keep in mind there are 4 cam sensors on your car, are you SURE you replaced the correct one? Typically on a rev-up you just swap the intake sensor with the exhaust sensor of the opposite bank since they're the same. Then see if the code follows over to where you moved that sensor.

 

yes - i replaced bank1 (passenger side)

 

Swap it to the exhaust side on the opposite bank and see if the code turns into P1084, then you will know for sure the sensor is bad. If the code persists then something else is going on and it's time to ring out the wiring harness back to the ECM and look for an open/shorted/damaged wire.