I am having this problem right now. I just changed out the bank 2 sensor

 

Well, for those that are following this. P0021 code is the death to my wallet. The gasket on the timing cover broke off and left some pieces floating around. Since the dealers don't sell the gaskets by itself I have to order a new timing cover which is $569. For those that know my car I had it polished and powder coated which I have to do again. FM

 

There is no gasket on the timing cover it is rtv. As well as the cam covers, water pump inspection cover, and tensioner cover.

 

There are 3 little rings inside when you pull the timing cover off.

 

The gaskets that are damaged are on the rear timing cover which I am sure is not polished. The polished front timing cover can still be re-used

 

^^Grave digger, lol

 

The p0021 code on the vq35de is totally different than the same code on a vq35hr. On the DE engine there is a intake valve timing solenoid with 3 bolts holding it on at the front of each valve cover. This is what gets toasted from low oil levels or from sludge because it operates off of oil pressure. If sensors are getting replaced for this, they are replacing the wrong part.

 

With a help of a few forums I will share my experience with my 2010 G37x sedan

My oil was low and very surprised because usually Royal Purple doesn't burn off that much. But it did probably at least 1 quart maybe 2.. don't know how long I was driving like that but about a few days after I topped it off I got the P0021 code.. After extensive research through forums and on Youtube they said try an oil change first.. I did and the code was still there with same problem.. I reset my ECU by disconnecting the battery and guess what... everything was back to normal.. from some guy on Youtube he said that the solenoid or something expands when the oil pressure is low.. so what I believe happened is it went back to normal after I reset the ECU and with normal oil pressure..
Resetting the ECU was key..

 

My 04 coupe had the P0021 code come up, I tested the intake solenoid and it was clicking, checked continuity of the wiring to the ECM, all was well. Replaced the ECM and reflashed it. Problem solved.

 

Thanks for the update

My problem actually was not solved.. I changed the intake solenoid but now I have a P0016 code which puts me on limp mode not allowing to exceed 3500 rpms.. also I have a long crank until my car starts.. I can still drive but not spiritly.. I have another car so I got lazy on solving this issue