2015 Buick Encore Issues.

[austenleach]

I have a 2015 Buick Encore that is giving me issues on repairing it and was wondering if there were any 1.4 gurus in here. Car has a surging idle, fuel trims are -35% and go to about -10% when idling up to 2,500 rpms. I'm posting a log for anyone to look at. Car is completely stock. Have changed the valve cover gasket, the intake manifold due to the check valve missing, the turbo with a new turbo, the one way hose from the intake boot to the valve cover, the MAP sensor, the MAF sensor, the boost pressure sensor, and the purge valve. Nothing has changed on this vehicle. Compression test shows 150psi across all 4 cylinders.2015 Encore 1.4.hpl

[TheMechanic]

I have a 2015 Buick Encore that is giving me issues on repairing it and was wondering if there were any 1.4 gurus in here. Car has a surging idle, fuel trims are -35% and go to about -10% when idling up to 2,500 rpms. I'm posting a log for anyone to look at. Car is completely stock. Have changed the valve cover gasket, the intake manifold due to the check valve missing, the turbo with a new turbo, the one way hose from the intake boot to the valve cover, the MAP sensor, the MAF sensor, the boost pressure sensor, and the purge valve. Nothing has changed on this vehicle. Compression test shows 150psi across all 4 cylinders.2015 Encore 1.4.hpl

This is what you need to concentrate on. Do the proper diagnostic on these codes. Specifically the underboost.
P0172 - System Too Rich (Bank 1) (Pending)
P1101 (Pending, Permanent)
P1400 (Permanent)
P0299 - Turbocharger/Supercharger A Underboost Condition (Permanent)
P0420 - Catalyst System Efficiency Below Threshold (Bank 1) (Permanent)