A bad exhaust cam position actuator ("phaser" to some) could cause a P0017 I think. More likely than a bad sensor. Now a slipped tone ring I'd buy.

 

NEVER clear codes unless you know what you are doing. Most codes will clear themselves after repair. Historic codes mean there once was a code that lit the CEL, they will clear after 100 clean ignition cycles. Pending codes don't light the CEL and might be transient or from the last ignition cycle. ONLY current codes need to be addressed.

If your SS has a Stage Tune there are probably quite a few crimped wires that need to be soldered; the original GM kit was installed by dealers and the instructions said to crimp, later a TSB corrected to solder then the next kit had a plug and play harness.
You can tell by a sticker on the gas filler that says 91 octane REQUIRED, not recommended. There are other cues under the hood.

I would check to see if the harmonic balancer is tightened to spec, lazy mechanics rely on impact guns.

 

Wassup guys! Just wanted to check in and give an update. Have added 7K miles since I acquired my HHR SS and its been great! I've done 2 oil changes with mobil one, put new rotors/pads(and flushed the darkest green fluid i've ever seen out), and knocked out some suspension bits. The lower control arms were a PITA to put new ball joints on with having to machine out the old ones. Swapped in new strut mounts but probably need to get some new struts, the old ones were wore out but didnt help as much as i wanted. Just ordered new sway bar end links and tie rod ends. Slowly but surely its getting better and better to drive around but just don't have the time to tackle everything at once.

 

Hope you got the right ball joints, only available from overthetopperformance.com.

 

According to the photo, if I zoom in the letters and numbers match DRD1

Here’s a closer look
nice to see the Moog bushings in place

 

The OEM struts can still be found. Grab 'em while you can.