When I got my 2006 2lt HHR the first thing I did was to order the factory manuel, expanse but well worth it, about $183.00.:propeller: bought OBD-11 scanner, got a price from Amazon and Wal-Mart matched the price was half of the list.

How is this helpful at all. It's the exact same thing my innova 3120 canobd 1&2 tool told me for the code

I know this is an old post but I can't resist. Did you expect to find a fix for every code in this thread?

I have the same problem, but is not related with air filter. I installed LPG system on my HHR. When i switch to gas start check light with code P0171. Any idea how to correct??
Thank you
Edi

If I had any idea what this means, I would move it to an appropriate place.

codes
 

would the listed codes be the same for the 2011 hhr 2.4 engine? thanks in advance for the reply.

Almost all Pxxxx codes are generic (I.E.: defined by OBDII), some of the other body codes are defined by the manufacture.

OBDII defines a core of codes, manufacturers may add more.

Air Bag Check warning
 

What does this mean?

Probably means you have a bad wire connection somewhere in the air bag system and you need to take that to the dealership and have it checked out.

Did you want a dictionary definition of "this"?