Been having a repeating code issue with my 2018 1.8. First was the purge valve……replaced twice and has stayed fixed, next was the P0011 code with multiple diagnostic tests resulting in multiple intake solenoids as well as cam gears and position sensors being replaced…….finally staying fixed. And now the newest repeating code. The P0411 air injection blah blah blah 
I’ve checked fuses, relays, powered both the air pump as well as the check valve and verified I have air contour of the exhaust pipe. Just replaced the check valve thinking perhaps the air flow sensor in side it might have left the chat, but lasted one day and the code is back. Other than the expected soot in the head and exhaust ports at the manifold, there was no flakes or obstructions I could see. Wondering if I am chasing a failing or glitching ECU?
I’ve checked fuses, relays, powered both the air pump as well as the check valve and verified I have air contour of the exhaust pipe. Just replaced the check valve thinking perhaps the air flow sensor in side it might have left the chat, but lasted one day and the code is back. Other than the expected soot in the head and exhaust ports at the manifold, there was no flakes or obstructions I could see. Wondering if I am chasing a failing or glitching ECU?