I have a 2009 HHR SS 5speed. When I reach 4000rpm the egine misses or stumbles. Does this from 1st gear too 5th. If you let up it stop. Other then that car runs great. I have no engine codes. Or trouble codes, no lights on. Does anyone have any suggestions for me to do or where to start looking?
​​​​​​​thanks

 

It could be a number of things, how many kilometres on the odometer?
Have you gone to get a code reader connected to your SS there might be pending codes.

 

Agree, if you haven't actually checked for codes, do so. Just because the CEL isn't lit, doesn't mean there are no codes.

If there truly are no codes, start by looking for vacuum leaks and boost leaks. It could also be ignition related, or poor fuel pressure. But all of these usually set codes.

 

I was also thinking a dirty throttle body

 

I have 192575km on the.car. I also have a really good scan tool. There are no pending codes, I did a live feed back test while driving it missed while I had the tool plugged in and no codes showed up. Could it be a spark plug or coil? The car sounds like I am hitting the rev limiter but I am only at 4000rpm, could the limit er be set at 4000rpm? Thanks for all yor input.

 

How old and what plugs are in it?

 

If the computer is not registering a misfire you are not missing. Look at fuel starvation.