My '11 2.4 lt surges in the 2000-3000 range when cold. tach goes up and down 3-4 times then settles down.

 

I split this off from a five year old thread, so we can start anew.

A few questions to help us narrow things down.

1. How many miles on your HHR?

2. Do you have a CEL currently illuminated?

3. Have you taken it and had the codes pulled?

4. If you've had the codes pulled, what were they?(Exact code numbers please, not "the counter person said")

5. Have you recently changed the air filter or otherwise removed the airbox?