[Mw999]

Hi we have a car new to us that intermittently develops the PO299 turbo under boost code and restricts the turbo from cutting in going into a limp mode

In the past it’s had a new turbo, waste gate actuator and cat and we’ve had a cat clean but it still brings up the code

Does anyone have an idea of the likely cause,  it’s going to Hyundai on Tuesday and would like any advice before then if you can help

Thanks

Martin

[Shambles]

Pretty sure we had a report in the forum several years ago, where at least 3 independent mechanics couldn't diagnose the issue, but the 4th removed the plastic wrapper from the air filter and all then worked

Seems there could be many causes of this DTC, including a pressure sensor.

Good luck sorting this out.