Limp mode sucks.....
 

First off mate.....good luck. Several members on this forum have had issues with their Z and unexplained limp mode and it can be difficult and frustrating to try and fix. I have an '11 nismo, stillen SC, uprev tune,
Bunch of other goodies and am in the process of trying to overcome unexplained limp mode also. A bunch of members have had limp mode occur with no code, so at least you have somewhere to start.

My problems started after my latest retune. I am throwing the P0011 code for bank A cam position sensor. I will be replacing both cam sensors and crank sensor as well as cleaning MAF sensor this next Monday. If this doesn't fix it my mechanic and I believe it may be the tune. I know my tuners really advanced the timing a lot and that may be causing some issues with the VVEL. I will post results to this thread.

So I'm burning off the entire tank and then will fill up adding "heet" I didn't mention that it has been a really bad winter here with a lot of below freezing temps in the negatives and a lot of snow. I frequently run my tank almost empty (bad habit and I didn't really think much of it until now). Wondering if there was just too much water in the gas and my tank. Last ditch effort before I take it to a shop. I'll let you know how it goes.

Hey guys, sorry for the delayed response as I was on Vacation. So I burned the entire tank empty by just running it for hours at a time. I filled it with 100 octane race gas and 93 (only 4 gallons of race gas), and added heet (water removal product). The car slowly but surely started running a bit better and the rpms would go through the entire range but it was still far from 100% engine light still on. I let it sit overnight and tested it the following morning. Ran great, sounded great, but CEL came on even though things were smooth.

Went on vacation and came back.

Started up and purring like a kitten. Test drove and viola perfect. Been driving it like a champ the past few days and its about 95% normal. Only a small fluctuation in rpms (100 or so) but doesn't seem to be a big deal for now. Does seem to be idling a bit lower but again these are nit picking. Looks like it was water in my tank and bad fuel. I'm so grateful it worked out the way it did. If I took it somewhere, I would have spent a fortune for them to try and figure it out. Thanks a lot guys, you were very helpful.

Hope that's all it was. I had to take my car back to dealer the other day because oil was still leaking and ran bone dry. I had pinging and loss of power, flashing cell. Once I added a quart of oil I had laying around it ran fine but I still took it in the same day. Come to find out because of low oil , they now need to replace cam sprocket. So maybe if you can have dealer check it out at some point.

Weird... I was leaning towards a damaged cam sensor or VVEL related issue as well.

I would pull the EFI fuses or unplug the battery, let all trims clear from ECU and go through the relearning process.

If no CEL's come back, then I guess just bad gas. Very strange -- good luck and keep us posted.