Well guys, my car really is beginning to become a joke, after about 50 mishaps, fire trucks, etc...
I get the car up and running and back to technosquare,

BUT, on the way there, the yellow exclamation point turned on. There was no check engine light, just the exclamation mark. This happened on the freeway while I was cruising. Checked the codes,a dn it was p0302 cylinder 2 misfire. The light turned off after I started the car up again without deleting the code. Technosquare TRIES to tune my car, but Tadashi says now that the boost doesnt feel right. Its boosting 9 psi at redline, but the boost isnt linear. It goes up to about 4-5 and the right at around 5500-6000rpm it soars to 8psi and then 9, all at once, almost like the belt is slipping, and then it catches. He thinks it may be the bypass valve. To top it off my afr is at 10.0 from 4000-7000.

On the way home, after cruising at about 75-80mph for about an hour, the same excalmation point came on. This thing comes on only after about an hour of freeway driving, never when im driving the **** out of it. Checked the code and it was cylinder 2 misfire again. This happened once more, with the same code. So I parked the car and took out the spark plugs. Theyre black around the edges, and pasty white on the tips. Now im off to autozone to get some spark plugs, and try and find something to cover up the bypass valve to see if its faulty.

 

Isn't the yellow exclamation for low tire pressure? I just checked the manual and that is listed. I get that after about an hour drive time since I no longer have the TPMS sensors on my new wheels.

 

Are you using the TS flash for fuel and timing ?

Ive noticed that the belt does grab better when its hot . The only two things that will effect boost on the SC is...the belt and the bypass valve . [if there are no boost leaks] You might want to try to put a new spring in the bypass valve...it maybe sticking and not sealling until you get enough preasure [ boost ] behind it to seal it up .

 

That seems logical..
What about that damn excalmation!? Is that only for TPS? and does it come on after an hour of driving becuase of my aftermarket wheels? I am getting a misfire code though even without the check engine light, very wierd, im going to call Nissan right now

 

I don't have FI but I get the exclamation point on extended drives even though I don't have them on the car.

 

That is the TPS.

 

Well I just found out that the exclamation is normal on long drives, which is funny becuase I never go that light before and I always drive the same route, really really weird. Oh well

Now I gotta fix this damn boost issue, arrgg Any ideas? Has anyone else experienced this? Like a little boost and then all of a sudden an isnae pull right after 5500 or so? It seems like I have a huge surge of boost.

 

yeah it's tire pressure


interesting that cylinder 2 specifically is misfiring. Multimisfire seems common, but specific cylinders seems like a possible issue to look into to me

 

yes i have the tps light only after 1hr or so of freeway driving with no tps in my aftermarket wheels .. just turn the car off and on again.. then try to check for the code..

 

From what you said # 2 plug looks like [ white ] doesnt that mean you are running lean ? You may have a bad injector

 

+1. Mine only turns on during highway driving after more than 50 miles or so.