Yah i have the same problem, i gotten a

P0300.Random/Multiple Cylinder Misfire Detected
P0174.System too Lean (Bank 2)
Dealership said it's due to engine oil consumption. it's at the shop right now getting a short block put in.

I got mine back from the shop yesterday and they could not find what's causing the p0300 code. They did contact Nissan support engineering who asked all the standard questions again. ( Gas type, driving habits etc.) They reset the 'learned' profiles and asked me to drive it and see if the light comes back. According to the service rep, he thinks it's flooding out the cylinders and causing a misfire. His opinion only. He asked if I was short hopping the car when it happened. I had to ask for an explanation. start engine to move short distance and cut off. Then start again to move short distance. I told him no.
I asked him if everything is controlled by the computer, how could it flood? No answer. They are still fishing and he told me we may have to wait till it gets worse so they can find it.

I think it all just comes down to the fact that the misfire code is to sensitive, all engines misfire when cold. Its just the nature of the beast, thats why the cars run rich when first started to keep that to a minimum. For whatever reason the ECU starts looking for the misfire code to early while the engine is still cold. In the software I use for GM trucks you can tell the ECM when to start looking for misfires, by pushing this out to almost operating temp you can get that pesky code out of the way.

Its more or less just an emissions code, I mean to many misfires would wreck havoc on your cats. But if it gets to that point you will most definitely be able to hear it misfire.

Had to take my car in because it kept throwing P0300 after my short block swap out. Ended up being a VVEL control shaft position sensor that was out of whack, per the tech.

Car feels better and the code hasn't come back (yet). We will see if it does.

Well my light came back on on 2/23/13 when I cranked it. 39 degrees and raining. Took it back to the shop 1st thing Monday morning and told them to keep it till they found something. They called me today to tell me that they had, per Nissan Engineer, cleaned all ground connections and added a ground strap. They have another strap ordered and when it arrives I'll take it back to them. I was told that if this did not stop the code from popping up about once a month he would have the engineer come to the dealership and perform more testing. He also told me that the engineer is trying to eliminate possible causes and does believe it is electrical.
My dealership and the people I'm working with have been great. I know intermittent troubles are the worse to find and do appreciate their persistence.

Corporate nissan sent in a specialist to take a look at my car. The specialist ordered to replace all fuel injectors and the ECM. They have it hooked up to a monitor and they are going to put 200 miles on it they said. I should be getting my car this Monday. I asked Corporate to buy my car back at this point and that is currently being reviewed. It takes 10 business days. I will know my next Friday.

Just got the dreaded P0300 code this morning. Guess it's a trip to the dealership this weekend. The only thing done the car are K&N drop-in's and a Borla CBE. This suck's I wanted to finally install my Gen 3's this weekend.

~Also notice that idle is sitting arount 1,000-1,200 rpm's when the engine is already warmed up.

So replacing all 6 fuel injectors and ECM didn't work because I got a check engine light on again yesterday. The good news is that Nissan sent me a letter saying they will comply with the Song-Berverly Consumer Warranty Act. I think I'll get a brand new Nismo now. I will miss my 40th.

Mitco..i tend to agree with you. Mine threw the p0300 code when i started her up in low teen temps. never idled high or low or did anything else out of ordinary. i erased the code and it hasnt come back since...been about a 1000 miles.

Since I last updated my saga I have put about 1000 miles on my Z and the light has come on twice. 1st time at 750 miles since last reset and then yesterday at 250 miles since last reset. At the 750 event I took it to the dealership and they added two more ground straps as recommended by the Nissan engineer and performed the steering lock recall work. Yesterday, the service adviser told me he would get back in touch with the engineer to see how to proceed.

My question to everyone is, How can I get copies of all service records for my vehicle since it was sold new?

I found out while talking with a salesman that my car has had two owners before me. The first put ~1500 miles on the car before it was traded and the second added ~6200 before it was traded. I'm wondering now if this vehicle has had this problem since new.
When I bought it I was show a carfax report that only showed normal service interval work. Now I'm concerned that some info may have been left out.

Go to a dealership and have then pull up the car's history by VIN. They can then print up anything run through NNA.

Thanks. When they call me to bring it back in, I'll ask them to do that for me.

Hey guys,

Just a quick update on my car...it's been 1k miles since I've gotten my car back and no problems. However, Nissan is still going to buy my car back and give me a VPP code that will give me $1500 below invoice on the 2013 PW Nismo. They are going to pay the rest of my loan and give me a check for 7k towards the Nismo. I'm gonna miss my 40th but man the PW Nismo looks sick.

Hi guys,

So I got this stupid P0300 misfire code also today. Turned it off and it hasn't come on since.

Do we know if this is a common/serious issue or not? My friend said it MIGHT be the spark plugs. Happened when its cold today like most of you. I'm about to put my car away for the season and by the time I bring it back out next year it'll be out of warranty. I might even be out of warranty now. I also have fun intakes/headers back. Any suggestions?

What year is your Z? Mine is an 2009 and tripped this code last winter. Car ran fine so i cleared the code and it hasnt come back since. I dont think Z's like the cold weather......