How to tell if tuned
 

Hi everybody!
I bought an 07 HHR 2LT 2.4 manual a few months back. It was originally owned by a guy who worked at a Chevy dealership. The car came with a thick folder of service records so it wasn't neglected. It also has a flowmaster catback.
My question is:
How can I tell if it has a tune or not? It's not incredibly fast but not sluggish either. In 1st gear it peels out without too much effort on 215 wide Goodyear Assurance.
Thanks a lot in advance!

Check the records, check the engine bay for stickers indicating a tune.
How about the fuel fill door anything saying high octane fuel required?
GMPP cat back was a Borla system.

Doubt you'll find any stickers. The OP has a 2.4 engine, so it would be an aftermarket tune if it had one.
The stickers (premium fuel required, etc.) were something you would get with the GM Stage 1 kit for the turbo SS HHR.

The chance of the OP having a tune on a 2.4 is pretty slim. Not too many tunes were ever done on the 2.2's and 2.4.

The manuals were easy to spin the tires. My 2.2 manual would easily turn over the 245 Extreme Contacts. Even grab second.

Only 2.4 tunes I’ve read about were Trifecta, no stickers included!

There are no stickers anywhere which doesn't surprise me.
I thought about something that could be a good indicator. I assume a tune would raise or delete the RPM limit. I could check that if it's still stock. Is it 6750 stock?

Can't go by that. It would depend on the particular tune and what changes were done to the files. The rev limiter could be set higher, lower, or same RPM. A limiter delete would be for an extreme tune.

:-/
I did check it yesterday on my way home. It cuts at 6750.
Is there any tune that's worth getting now that the trifecta is not available? I searched but it seems like there is nothing out there. I don't know how to tune but I might just use my HHR to learn. Only if I had the time....

You could take it to a GM shop for service. They are supposed to check with the Tech2 to see if renegade firmware is installed. First step in almost all performance related diagnostics.

I think I'm gonna learn how to tune. I always wanted to.
I service my own cars. Don't trust the dealer. My equinox was the only car I took to the dealer because of warranty issues (which it had quite a few). I change the oil myself on it and they b'beep'ed about it heavily. It had an oil burning issue at 35K where it used over a quart of oil every 2000 miles which they said was normal (on a 2011 car!) and didn't want to deal with it because I had no records of oil change. The oil burning issue was a known problem that GM released a service bulletin for. So I called GM and went back to the dealer with a print-out of the bulletin. As I was arguing with the manager a big red window popped up on his computer. It was a message from GM. He asked me if I called them. I said yes and his tone changed immediately. They rebuilt my engine.