So last night I was getting a video of the new exhaust I went to do a 2-3 NLS and it fell on its face and started missing it has done this twice before but both times I instantly let out but for whatever reason I stayed in it last night and within a few seconds the CEL started flashing. By the time I turned around the CEL was gone and the car was running fine.


So I did a quick search and I cant seem to get a straight answer on what caused this or what may be wrong. Engine was at operating temp I did shift kinda slow but I don't think it was slow enough to cause a problem. When that CEL started flashed I thought I fucked something up. So to be honest I don't want to even try it again I think i'm done with NLS its not worth it not trying to hurt my car.

Skip to 1:50 if you just want to hear the misfire.


Any thoughts?

WOT AFR's range anywhere from 12.5-13.2. I did another pull on the way home just to see if anything felt out of place and it was fine but it was 13.1 AFR at the top of 3rd.

 

Are you tuned?

 

Was the engine cold? Mine misfires when it's colder.

 

Yeah I don't do pulls unless my car has been running for a bit.

 

Probably the misfire caused the flashing check engine light

 

Stock tune. And engine was at operating temperature.

 

When I had my white car and went out next the the field and NLS even with my car warmed up, it would misfire on NLS. So it's normal in very cold places on stock tune.

 

Mine would happen around freezing temp and just below. Needed to pull onto a very busy highway right after work.

 

Well the flashing check engine light just means massive misfire(catalyst damaging levels of misfire)

Get the car scanned there may be pending codes. Like P0300, 0301, 0302, 0304

P0300 - Random/Multiple Cylinder Misfire Detected
P0301 - Cylinder #1 Misfire Detected
P0302 - Cylinder #2 Misfire Detected
P0303 - Cylinder #3 Misfire Detected
P0304 - Cylinder #4 Misfire Detected

A code P0300 may mean that one or more of the following has happened:
Faulty spark plugs or wires Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked/leaking EGR valve / passages
Faulty camshaft position sensor
Defective computer

A code P0301 - P0304 may mean that one or more of the following has happened:
Faulty spark plug or wire Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

Get it scanned and give us more info. It may have just been that NLS wasn't performed fast enough, or you tagged the rev limiter, that's a pretty hard hit on the rev limited when going from 2nd to 3rd. Either way, cehck the plugs and the gap if they are shot, bet replacement for them is the stock AC Delcos #41-108.

 

Thanks for the info. Is there a way to scan it other than tech2? plugs will be done asap. The car is running fine I went on a 7 hour cruise today and played around quite a bit with no problems its just a NLS issue.

 

sounds to me like u didn't nls properly. that or ur injector seals don't like it. machine gun misfire is usually injector seals going out.

 

Any code reader will work

 

^this

and just about any parts store will scan them for you, or you can buy one pretty cheap as well. Also with the CEL not being on, it may not be currently throwing a code, but its possible there is stored/pending code(s). I would almost say that after as much driving as you have done the code may not be stored or pending anymore.

Also with the catless DP, you should have the car tuned, pretty sure the fuel trims are going to be out to lunch.

 

Ur a/f is fine for stock tune. That's what it is. Ur flashing cell is a missive misfire , probably on all cylinders. Caused by doing nls to slow or doing it when oil temp is to low. U can have ur coolant temp up, but if oil temp is lower than 150, u can cause misfire like this. Iv done both shifting to slow and having low oil temp and got flashing cell on both.

 

stay off the rev limiter.

 

^^^This and I recommend no more lift shifting problem solved.

Personally I did it once just to say yay i did it and yea that was fun, But with all the potential damage and problems behind such a new system I would just stay away- This is just my 2 cents to each his own.

 

GM would of never added the nls function if it couldn't handle a stock tune.

Just think they gave to warranty the drivetrain for 100k miles.

 

[lol]

 

^^
Just my opinion no actually facts. Thanks

 

It handles the stock tune just fine.

But the car has to be in fully warmed and the shift has to be really good.

 

The two most constant variables I've found to cause this is shifting too late and very cold outside temps. Remember the tach is slightly delayed depending on which gear your in.

I have heard others say it could be caused by shifting too fast which I find hard to believe. It even states in the owners manual, the quicker you shift, the better it will work. As far as shifting to slow, the NLS feature stays active for 1 second before it exits NLS feature and resumes normal over rev protection.

 

NLS is hard on your car. I don't care who you what skills you have.

Just because GM implemented the logic in the PCM doesn't make it any less hard on your clutch, syncros, shift forks, shift cables, axles etc etc.


Another Imperial Blue sedan!

 

I don't nls but I'm tuned. If I was stock I would but not alot. I just don't trust it fully with the way gm cuts corners