My HHR has been starting rough after sitting all night, after a few minutes it runs fine. I used my Car MD scanner,and got code po172 -that is a generic code, has anyone else had this problem and if so how did you solve it. And yes I still love my baby, although my wifes new equinox is smoothhhhh .LOL

 

What all have you tried to "fix" the problem?

 

The first thing I would do is check the fuel pressure. Check it at idle and after you shut off the engine see of it drops or holds rail pressure.

Your code is for a rich condition it is p0172. The second digit in the code number is a number not a letter.

The fuel pressure test will check to see if one of the injectors may be bleeding down over night.

 

Search P0172, there are several threads from dirty air filter to Evaporate valve and so on.

 

Thanks and come to think of it the air filter has not been changed in a long time, I will start there. I did have my fuel system flushed as I was overdue for that, been out of work, so money has been tight

 

Check your MAF sensor connection after you change the air filter

 

I don't remember the exact code I had on my HHR, but a week after I bought it, the purge valve went bad and it was difficult to starting. It is the valve found just below the oil filler cap, it has a vacuum line at each end and one plug. It is rectangular in shape. If you can blow any air through it, it is faulty and maybe your problem. It is simple enough to check yourself and easy to replace, if you're handy with tools. The cost was $46 for new one at NAPA.

Something to check, and fairly easy to do yourself, good luck.

Clink the link to see what it looks like.
http://www.carid.com/2006-chevy-hhr-...-16857958.html