PeppyheadVette

Bought the car, has Corsa Exhaust and CAI.
I got zero paperwork with the car but I got it inspected prior to purchase and all good, well nothing super bad anyway.

I have no clue if it has a tune or not. It's obviously extremely fast but I don't have any other non tuned c5z's to compare it to so is there a way to see if it has a tune or not without bringing it in somewhere? What about the diagnostics buttons on the dash?

thanks.

grantv

I don't think there is a way without hooking up, but watching for replies. The PO wouldn't need one for those 2 add-ons, so it's kind of unlikely.

MY03C5Z

Some tuners will put their label on the pcm, but usually only if it was done as a mail in tune. The pcm in the c5 isn't exactly the easiest to access though, lol...

CalF

Most if not all tuners will disable the 1-4 skip shift and dash light.Some will also change to a cooler thermostat and change temps for fans to kick on.

grantv

Good points... a 1-4 skip shift eliminator with dash light delete could also have been installed, so the OP would have to check for one. Fan temp change would be tough to find.
Peppyhead; does your Z force a 1-4 shift at low speeds, light pedal?

alextz

If you know someone with HPTuners, they can scan your PCM and compare to a stock file. If you are in the chicago area, I could do that for you.

PeppyheadVette

Shifts normally, so it doesn't force me to go 1st to 4th.
I was thinking of getting Long tubes and a tune and I would hate to waste money if it's already done. Problem is in I don't know if the couple of shops here in calgary would tell me if it already had a tune.

grantv

If it lets you shift into 2nd at low throttle then you either have a tune or a skip shift installed. Check into the different types, then see if there is one on your car.
If you install LT's you'll need another tune regardless.
Grant, Kelowna

Scotty2000SS

You will need a tune either way if you get long tubes.