Weird thing happened last night. First I was very, very lucky that a deer did not destroy my HHR. But in order to avoid the deer, I had to slam on the brakes. Immediately after, the CEL came on. I then had to stop to get gas and to look at the bumper to make sure there was no contact made. When I went to remove the gas cap, it almost felt like it was not on very tight. I'm not 100% though because I was still in shock from almost hitting that dang deer!
Is there anything else I should check or just wait to see if the CEL will reset?

Thanks.

 

The CEL is probably from the loose gas cap, it throws a EVAP code. It would seem to just be coincidence that you noticed this after your hard brake.

 

Apparently the gas cap was the issue. The CEL went out yesterday.

I was just concerned as this is the first time I've seen the CEL and I was afraid it could be something more serious. Although I did not notice any issues while driving with the CEL lit.

Case closed.

 

Mine went on also, but after I made tight U turn. Stayed on for about an hour and went off. Weird!! The car is temperamental. Long as it goes out don't bug me none...

 

Check this link. Might be your problem, might not.

https://www.chevyhhr.net/forums/show...2415&page=3#23

 

Thanks ChevyMgr!
I will check into this when or if it does it again. Seems to me that my HHR has some issues but I will probably upgrade to the SS before it goes out of warranty. I'm not too worried long as it's not always on... BTW is it possible for dealer to check even if it's not on? Just wondering if I should even bring it up when I go in for the front end this week. Thanks again..

 

The trouble code is now stored in the memory so it can be diagnosed. I would tell them about it when you go in. There is another fix to reprogram for certain codes or replace the fuel injectors.

 

Thank you. I will let them know then.

 

OK, my CEL came on again so I went to AutoZone and they printed out code P0128 which is "Coolant temp stays low" or something close to that.
I've already checked the coolant level and it is normal. My only other guess is that the thermostat may be stuck open. Does this sound right?
I've successfully changed out thermostats on other vehicles, so I would think the HHR would not be difficult. Are there any suggestions before I start?
Thanks.

 

I've had 3 cars in my bay in the last 2 months with this code. (Toyota vehicles, not Chevys.) All three had bad thermostats.