burning oil and false codes?

[Renee209]

Hi ya'll! I have a 06' S40 2.4 (non turbo) I bought in 2018 that had about 60k mls on it. However, it was not disclosed to me that it had the famous sunroof leak & consequently I got a large amount of water inside the vehicle. For periods of time windows wouldn't function, door locks, instrument panel completely goes out and the radio hasn't work for a very long time. I have done all the obvious things (checked fuses, etc) and dried the car out as quickly as I could but I'm sure damage has been done. My question is, will that water damage cause the computer to throw false codes? I brought my car into a mechanic I trust recently because I had an "urgent engine" red triangle on the car but my code reader wasn't getting anything. So he reads it and has SIX PAGES of codes, among them is a "mileage manipulated" code (I verified w/NHTS, Carfax, and other reputable spots but the mileage is right on). It seems to go away w/tightening of the gas cap so I'm replacing that but I'm concerned about the codes, there were a lot of really bad ones on there. Car seems to run fine except that it burns a lot of oil, I use synthetic. I'm thinking to start w/replacing the PVC valve/sensor. I do as much work myself because I enjoy it plus it saves $$. Thoughts? Thanks!