The first code is a complex calculation that involves the oxygen sensor and a few others to determine if you are operating at peak combustion efficiency. Insufficient air, excess fuel, injectors that are over-supplying, or a faulty oxygen sensor are common causes.
The interesting point is the link to the fuel tank pressure sensor. If that sensor is failing because the tank is too pressurized, and you are running rich at the cylinders, I would suspect the fuel pressure regulator is faulty. A fuel pump could cause that, too, but generally when fuel pumps fail, they don't over pressurize.
The interesting point is the link to the fuel tank pressure sensor. If that sensor is failing because the tank is too pressurized, and you are running rich at the cylinders, I would suspect the fuel pressure regulator is faulty. A fuel pump could cause that, too, but generally when fuel pumps fail, they don't over pressurize.