Calling all Audi master techs
2015 Audi a4 quattro 2.0T, engine code CPMB (flex fuel)
I bought this car with a dead cylinder, turned out to be a burnt exhaust valve. I pulled the cylinder head off and I had the valve replaced and cleaned, decked, the whole 9 yards. I did all the timing chains including the balance shaft chain. I actually didn't do the oil pump chain because I couldn't do it without taking the pan off, but it seemed fine and I read many people say they've never done that chain.
I've put about 100 miles on this car and now I am getting a low oil pressure light at operating temperature at idle. I hooked up a gauge and confirmed it was 12psi. The service manual says it should be at 17-29psi. All the other checks at 2,000 rpms and 3,700 were within spec, just on the low side of the tolerance.
The other issue I'm getting is the air conditioner doesn't work. I brought it to a shop and I had the refrigerant filled, but there are some AC codes on that module. I'll attach the codes that it threw.
What am I missing?