The MAF and the lambda are at opposite ends of the fuel calculations. The MAF reads the amount and temperature of air coming into the engine, and the ECU then puts in a certain amount of fuel based on the stored map. The lambda then checks the exhaust gas for oxygen and essentially adjusts the starting point of the fuel curve in the ECU map to compensate.
So if the lambda is not working correctly it will upset the fuelling. Equally, if the MAF is failing it will mean that the initial fuel calculation is incorrect. That on its own can give a lambda error as the lambda will be reading outside its range.
You need to read the codes and see what they are telling you rather than just resetting/deleting them. For example, is the lambda error for mixture outside the operating range or a voltage problem with the sensor? Without the specific codes and correct explanations for your car its difficult to give more helpful advice.