LHU (A20NFT) P0299 and P0113 Codes

Hi, I have a Buick Regal (Just a Vauxhall Insignia in the States) which has an intermittent issue with these two codes - P0299 and P2261. P0113 also appeared a few times.

Initially, it would go into limp mode and constantly require the codes clearing, and it would have very little power and struggle to get up to speed.

Initially I went to a mechanic who did a smoke test and found a boost leak and replaced either the air intake pipe or charge pipe (I dont recall which) because he said it had a crack. Afterwards, he said he couldn't find any more boost leaks.

I replaced the diverter valve initially with a billet aluminium one from ZZ Performance, and then replaced the solenoid with a OEM GM unit. This is on account of people online stating these are the two most common failures when you get these codes. I also cleared the MAF sensor with a cleaning spray. When doing so I also checked the turbo turbine for play and it was completely stiff with no lateral movement.

That made a considerable difference, and it has made it much quicker. It still goes into limp mode but not as often. However, I still get two codes, and if I accelerate aggressively, it will eventually fall into limp Limp mode, but not nearly as often. Weirdly, it looks like the engine light shows up more frequently.

Does anyone have any suggestions?