P0234 Turbo overboosting then going limp
 

Hey guys, I've been driving a 2008 HHR SS passed down to me from my dad for the last year. Last month I started losing boost randomly then suddenly I got a CEL and every time my car got past 10psi the gauge would max out then lose boost and the car would no longer make boost until it was turned off and back on. Now the CEL is off and the code won't return but my car on WOT has the boost constantly waving up and down from 5-10psi but no longer goes into limp.

The code I got was P0234 Turbo over boosting.

Does anyone know any solutions?

I noticed some threads say to clean the wastegate solenoid, others are saying a new wastegate solenoid which means an entire new turbo since the wastegate is no longer sold separately, I also saw one saying to adjust the wastegate to reduce boost.

If it's something simple to fix the issue I would love to do it and keep the car running at full power. I don't want to spend the money buying a new turbo but I've truly fallen in love with the car.

Thank you for checking my post out I appreciate any information.

Bought the part from ford it doesn't not come with the hoses or clamps so you will need to buy those separately if you need them.

Hi, :welcomewagon: to the forums!!

Yep, you most likely need a new boost control solenoid. You're in luck, one of our members just found some very promising information.

Check this out
https://www.chevyhhr.net/forums/ss-s...olenoid-65238/

And yes, I have been through this same issue. It can be changed without removing the turbocharger.

Thank you for the info I will buy the part and give it a shot this weekend hopefully it fixes the issue, ill post an update once I do it. This seems very promising as I've been hitting dead ends all day until now.
Is there a guide anywhere on replacing the boost solenoid, I don't wanna go in blind and break anything lol.

You'll need a T30 torx bit for the screw that attaches it to the turbocharger. The hose clamps will very likely break when you try to remove them. If memory serves, one of the hoses is bonded to the solenoid, so remove the hoses and solenoid as a unit. Ok, found it, check my post #7, I show which hose is bonded.https://www.chevyhhr.net/forums/ss-s...42/#post802058

It sometimes is the electrical connector, it can get brittle from heat cycles, just like the clamps. Pretty sure I did it all from under the vehicle. The site where I had found a new pigtail is no longer operating.

Ohh boy I hope my connecter isn't brittle. I know there aren't any hhr ss in junkyards around me. I'll try to locate a pigtail just in case, rather be safe than sorry.