"Mothers cars" often suffer from deferred maintenance, I know my wife just ignores new unusual sounds and feelings, so did my mother.

 

I’m wondering how the battery is? Above 12.6 volts? Or below 12.4 volts static charge? If the HHR sat for a while, it could simply be a dead cell battery

 

So here’s where I went wrong.

1. a while back I removed the air intake and accidentally moved the throttle body hose so it wasn’t snug and had a small gap where unfiltered air cold go in.
2. got an alignment but then did more suspension work
3. removed throttle body to clean it out. Put it back in correctly, forgot about relearn revved the engine while in relearn throttle body and it got the wrong idle rpms readings.

update:
I was aim a road trip with multiple state crosses we stopped in Vegas before continuing because the car wasn’t going to make it up and down those sharp turns in the Utah and Colorado mountains. So we stopped to get another alignment/ second opinion on the problem.


Turns out we did mess the previous alignment when we did more suspension work. Also turns out the back wheels had **** alignment. Alignment so bad the front tires looked inwards from front bumper and back wheels looked inwards from rear bumper. So front looked like upside down V and the rear looked like a V. Got that done and while there they gave me a really good price on new tires I couldn’t turn down. Turns out that’s exactly what it needed the suspension feels done. Runs smooth and straight no ESC or ABS lights turning on randomly. We def go out moneys worth because them Colorando mountain turns are something else especially at night.

In terms of engine. After throttle clean which was really dirty and even had a black sludge, I’m attributing to the hose being half on half off and letting unfiltered air and what not in(it was raining previously). I messed up the throttle relearn and have it the wrong reading by reving the engine while it did the relearn. Well looked up how to do another relearn without removing anything and after that it fixed the idle rpms being high, park rpms being at 2500 and the car feeling like I was pushing pedal when I wasn’t. Also fixed the car feeling like it was limping fowards on drive.

battery issue never learned what it was but never happened again after all the fixes I did.

drove the car from California to Nebraska with multiple gas stops and food stops. Didn’t have a single problem and no engine light ever came on.

car is practically done now besides a couple more changes.

car has definitely been very frustrating with all the problems it’s had but you guys are right it was neglected by my mother. So now I’m footing the bill for all that neglect.

 

Sounds like now you can cruise along and enjoy the ride! So sorry for your loss, but your Mom would be very Happy you are enjoying her HHR!
Keep it clean and drive it often!

 

It relearns every time you let it idle for 10 minutes.. More likely something is holding the butterfly open, might have broken the nylon bears.
The rear alignment is means either the "axle" beam is bent or the hubs are bad.
I found that some LCAs are a tiny bit shorter that makes the camber off.
Testing the hubs/bearings is just push/pull, you should not feel any end play. If you have a micrometer it should be less than .015 inch.