Check Engine Light 2010 HHR SS
 

I got a check engine light about 3 fill ups ago. I know I need to run codes but just have not had the time to get to a auto parts store to ask if they can.
The car runs fine other that just two things I have noticed. It has a rough idle for about the first 30 seconds after a start up. And after a fuel fill up, it fails to start the first time. Second time, it will crank for about 5 seconds and then start and runs REALLY rough for about 20 seconds. Any ideas?
I'm on Amazon now and a new fuel cap is only $11 and thinking of buying this to see of that makes a difference.
I also noticed the air/fuel mix is about 16.5 at normal idle. I'm pretty sure on the pas this was at about 15.

Evidently, something is malfunctioning. The OBD2 code would point us in a direction to help you out. Without codes we can only say "something broke".

Don is right - something broke.

Did the DIC message anything about fuel cap issues?

If if you can , drive over to your local parts palace and get the codes read. Otherwise, you could be spending money unnecessarily

2010 HHS SS with approximately 72,000 miles. All stock no mods.

Went to Auto Zone store and ran the codes and this is what they got:

P0010 Intake Camshaft Position Actuator Circuit
P0011 Intake Camshaft Position Timing - Over Advanced
P0496 Evaporative Emissions System High Purge Flow
P0451 Evaporative Emission System Pressure Sensor/Switch Range/Performance

Their system gave a suggested repair of changing the Variable Valve Timing Sprocket

Read these for more information

https://www.obd-codes.com/p0010

https://www.obd-codes.com/p0011

could be the VVT solenoids, could be a timing chain issue developing.

https://www.obd-codes.com/p0451

https://www.obd-codes.com/p0496

now checking these involves looking under the HHR , and yes it could be the fuel cap.
But it can be other problems

I would crank the fuel cap down tight, and if that doesn't change things, then look for an EVAP system vacuum leak. The hard starts sound like a vacuum leak. Check for cracked or disconnected vacuum connections. Check the line from the purge solenoid to the engine closely.

I found a cracked line on the wife's Traverse in the PCV system, but it caused rough starts and doggy performance until it warmed up. Hers seemed worse in the cold, but had been around for a while before I could figure it out.

If you do find something, do the "lobotomy" - disconnect the battery for a minute or so, and then restart and the camshaft sensors should then be happy. They will reset themselves eventually, but that speeds the process.

Changing sprockets is insane! Changing VVT valves is what they meant. If you can change the air filter you change them.

Then replace the EVAP purge valve (the one under the hood) this causes hard starting. Another easy one. If that doesn't fix it there is a broken EVAP line. The reason it popped up after a fueling is that it only runs when the tank is between 22% and 88% full.

Don't pay labor unless you don't know which end of a screwdriver to use as a hammer.

I am not much of a car mechanic but I am hugely handy on home repairs and renovations. So I am pretty confident if its explained to me...I can do it on a car also.

I googled Evap purge valve for HHR and the only thing I found was changing one under the car at the tank. There is one by the engine?

As for changing the VVT valves. That does not sound easy but yes I can change an air filter. lol. How easy is this and where do I begin?

Thanks, Ill check for the leaks once I find out where the evap purge valve is by the engine.
So I do the lobotomy disconnect only after I think I found and fixed the leak?

BTW guys...when I fix the right thing, will the codes and light do out, or do they need to be manually cleared?