I just purchased a HHR SS with stage 1 and it goes like a bat out of ....., but intermittantly restricts boost pressure to 5 psi. Is this a common problem with a known solution??

The dealer reprogrammed to stock flash, soldered the stage 1 connector and pushed it out of the shop... very disappointing performance now.

 

Welcome to the forum!

Sounds like limp mode which is common...There is multiple things that cause it, mine was the after market air filter...You have a CEL or trouble codes?

 

Common? Not all do it. .

What is CPO?

Codes?

 

I'm assuming certified pre owned

 

I am guessing it's an auto?

 

Yes, sorry... CPO = a certified pre-owned HHR SS. I don't know if the soldering solved the 5psi boost problem, but I did loose stage 1 performance with the stock reprogramming by the dealer... do I have any way of recovering my Stage 1 programming? Oops, forgot to mention that this is a 2010 with warranty, which I would like to retain.

 

The "stage 1" programming that was put in, assuming by a dealer, would be linked to your VIN. Why your dealer put back the stock program is a mystery. They should have checked your upper & lower TMAP sensors and connections as a starting point. Of concern is the lower TMAP wiring near the A/C compressor. Look for chafing interference, hard to see. I have a 2010 with the stage 1, have had sensor failures as well as connection issues. All were solved with soldering and sensor replacement. Did they even check for codes? Reset the codes ? There are two sensors involved, either one of which can cause the problem you describe. Under warranty? Get it back there and insist on reloading the stage 1 program which should be calibration P/N 12637246(auto) or 12637247 (manual). Hope they get it right for you, 5psi in limp mode is not a good way to drive. Request that they refer to Specifications Part Number 19212711.

 

The GMTU is covered under your vehicle warranty. They should reflash it to the Turbo Upgrade flash. If they balk. Take it to another dealer.

 

If the upgrade was done at a dealer and programmed through TIS2WEB it is impossible to reflash it to stock. That VIN would always be linked with the upgrade no matter what dealer tried to reprogram the vehicle. Once done you can't go back unless it is done with an aftermarket reprogramming tool.

 

You can verify it for yourself free of charge here: http://tis2web.service.gm.com/tis2web

Then click on ECM, and select "Engine Operation ", click next in the upper right corner, if it was done properly one of the calibrations listed should say "Calibration for stage one and stage two kits"

No, I don't know what stage two is, so please don't ask:)