ItsMrG

Disclaimer:
Hi I’m still semi-new to the brand and forum. So I apologize if I am not up to date on the brand lingo and site functions. I am also on mobile.

Onward to my issue at hand; I have a 17 GLS550, yesterday afternoon check engine light came on, there is no difference in performance or the way it feels. No noticeable anything. I have a very basic scan, used it today to scan it, came up with code P0299 Turbocharger A under boost. From my basic understanding of turbos, I checked the air-filters they’re clean and not clogged. I checked the air inlet tube with the felt like section that likes to rip/tear. I recently replaced the driver side because of a rip in it. Today I noticed the passenger side had a tear in it. Could this be the issue? I don’t think it would be. My reasoning is under post would imply not enough air going in to turbo or it’s getting dumped at the waste gate. But I have been wrong before. Anywho just ordered a passenger side air intake hose because needs to be replaced anyway. But I am not familiar with this engine and/or turbo set up. Any help on trying to self diagnose this code would be greatly appreciated.

bwaldmer

When I got that code I put in new air filters and cleaned out the air filter housings. Error then went away inside 20 miles of driving. I'm not saying this is the surefire fix but it worked for me. I put in the OEM paper filters. Thought about K&Ns or other 'high performance' filters but from what I read the OEMs are best for a turbo charged engine.

ItsMrG

thank you! I will pick some new filters up and try that. I looked at mine and they seemed good but who knows? Definitely worth a try. Thanks again

ItsMrG

Thank you for the air filter suggestion, I dropped new filters in and instantly when I turned on the car CEL was gone!!

bwaldmer

Good to hear that simple fix worked for you, too.