I just had the P0299 with the P0405 code together, and right after it coded, the turbo started to fart.

This is with engine thoroughly warm, with me flooring it to clean it up.

Funny, because as soon as I erased the codes, the turbo fart and other problems ceased.

So the VGT solenoid somehow, have something to do with this/


In the past, I had the P0405 several times after the EGR was cleaned, and once when the engine will not accelerate past 10mph that I put down to carbon stuck on intake or exhaust or EGR valve jamming it open.

I cleared that problem by pulling over, reving it, and it cleared (and codes were cleared later).