I have a similar problem with my 2004 350z.. Two shops said it was the ECU. So I found a replacement ECU and am going to have nissan re-key it tomorrow. I'll let you know if it fixes the problem.

Are you also having problems starting the car randomly?

 

No I'm not having any start issues . I was having idle issues due to me trying to clean out my tb with out knowing the proper procedure but after I put in a new battery it cleared it self up and idles perfect now and not at 1000.i just checked the injectors with an ohm tester and they tested out fine although doesn't mean one could still be cloged so I'm stumped . Guess ill just have to get a new set of oem plugs this week.

 

yah like i said if not hurting performance i wouldnt even worry too aweful much

 

Just sucks I have a code that me or no one can figure out

 

Bumping an old thread , so basically from October till last night I had fixed my random cylinder #2 missfire up until last night when put of nowhere the same code came back .

Things I've done so far in terms of addressing the problem .
1. Changed all plugs wit oem
2. Replaced valve cover and gasket with oem
3. Replaced cylinder #2 fuel injector with oem

Now the car has 102,xxx miles and still seems to run idle (550 roughly ) and pull fine . What else is there to do ?
I swapped my cylinder 2 & 4 coil packs to see if it makes a difference after I did the reset /relearn procedure so I will keep this updated .

 

Nothing yet , no light or any difference . Btw my car is idling at about 500-550 rpm. Any one else can chime in ?

 

Any updates on this, I'm having a similar problem. I installed the NWP TB with a Furookie 3.5" intake along with a 3.5" Blox velocity stack filter. Before start up i expected a rough idle and there was. After I performed all the steps in resetting (re -learn throttle, reset ecu ect.) , I still had a rough idle, lost power and the car felt like it was chocking while driving. Took it to a shop this morning and the Mech. said I'm throwing a code, Misfire cylinder 2. I'm thinking of changing the coil-pack and taking it back for a re-tune due to the mech. saying he can't due much because I'm tuned with uprev. (Does that make since?)

Had a similar problem on cylinder 6 about 10 months ago, changed the coil-pack and car started up and ran just fine, got all the power back and stopped the STI exhaust sound.

 

So heres the deal, I spoke to Arron at NWP (Great guy, very patient and full of knowledge) He said since i installed the Furookie intake the bigger diameter is going to throw the MAF sensor off. Which will lead to all of the above. He stated the car will start to dump large amounts of fuel and make the car run rich (not drive-able). He recommend i throw the previous intake on, make sure the car turns on and idles right. Drive the car down to the tuner shop and on the dyno, swap the intakes. I will try this and let you guys know what happens, plus #'s.