[thstone]

P1126 and P1133; The engine is running lean so additional fuel is being added by the computer to try to compensate for this condition but the maximum limit of adding fuel has been reached.

Likely causes;
1) The MAF is not mesauring the amount of incoming air correctly and needs to be cleaned or replaced
2) The MAF is correct and additional air is coming in from somewhere else (like an intake or vaccum leak).

P0154 - Oxygen Sensor Circuit No Activity. This usually means that the O2 sensor is dead or there is a wiring problem.

I'd work on the P0154 problem first. Once its fixed, the other codes may disappear.

If not, then start to diagnose the rich fuel codes by disconnecting the cable to the MAF and driving for a short while. If the car runs better, replace the MAF. If the car runs the same or worse, there is likely an air leak somewhere.