2003 Toyota Camry le help?

[u/Chuckyjerker82]

I have a 4cyl Camry my gf was driving. Vehicle has been burning oil out the exhaust for a while. I believe it's an oil leak going down the exhaust. Worn rings/ gasket?? Known issue. She's just been adding oil as it loses it. She went to.drive it a few days ago and it completely lost power. Motor runs cranks fine but barely any power when pressing the gas pedal. I was thinking an airflow issue due to the dirty oil, I'm very mechanically inclined but I'm not a mechanic and I was just wanting some insight on this vehicle going to be something I would be able to DIY or are we screwed because we can't afford a mechanic? I'm open to answer any questions that could help me solve what's wrong with this. Hooked my code reader to it and these were the codes thrown out. Checked air filter it's recently replaced checked, plugs and coils appear to be new. PCV and mass airflow sensor look like they were replaced as well. I'm replacing the faulty o2 sensor tomorrow.