I have a 2002 Miata and it has codes P0011 and P0012. Every time i erase the codes and drive the car when its starts warming up it idles like crap and it wants to shut off. Then as it reaches to operating temperature it runs fine. The codes is saying that Camshaft is over advanced. I tried replacing the Cam sensor but it did nothing to fix the code. I want to know what is the cause of these codes.
Clarification: Mileage, and which engine?
You have a problem with your variable valve timing. Could be dirty oil or sludge buildup in the cam phasers or worn-out components.
https://www.obd-codes.com/p0011
https://www.obd-codes.com/p0012
Codes indicating the cam actuators are stuck in the advanced position. Possibly due to dirty oil that thins out when it warms up. Changing the cam sensors wouldn't help.
Try an oil and filter change to see if it frees them up.