Mine did it twice and it was both before my car didn't get into opperating temps if I let it warm up it won't happen and I'm getting my timing tables retuned

 

If your car is not up to operating temperature it will happen almost everytime because the during the NLS the ECM retards timing (ignition and cam, I believe) and dumps in a ton of fuel to keep a load on the engine so the turbo stays spooled up. If you take too long to shift you are staying in that retarded timing too much fuel mode too long and you will most certainly misfire becasue the fuel does not have enough time to fully burn. If you are not up to operating temps your car is still using the warm up fueling and cam tables so it is way me likely to misfire whan you attempt a NLS. Too much fuel plus less time for it to burn equals almost certain misfire. Those of you who have your cam timing tables messed with that could exacerbate the problem if too much adjustment is done that could be why you are misfiring.

 

anyone who is no lift shifting or even going wot when the car isnt fully warmed up should give up their keys

 

X2.
ECT should be at least 180 before you romp on it.

 

I have seen some people having issues trying to NLS from 1st to 2nd mostly. I guess the RPM you end up at in 2nd has a lot of load on it with the excess boost. Some of the cars that have supporting mods I have raised the limiter up to 6,700 and they don't experience that load issue. Also, the solstice and sky cars don't have this issue because they can't NLS. This is a Cobalt issue that I have seen.

 

HOLY BIG SIG BATMAN