causes of it going bad? Also does there need to be a vacuum line conected to it?

 

From when I owned a Chrysler and had to replace my MAP sensor every 12-20k miles and my discussions with my mechanic. I don’t know if this holds true for the Maxima.

The computer only only reads the MAP sensor during the warm-up phase of the car. This is because the oxygen sensor would give the computer a false reading when it tries to determine if it should change the air/fuel mixture. The oxygen sensor would not work until it was warmed to operating temperature (similar to catalytic converters). When my MAP sensor would fail, the computer would put the car in limp-home mode (full rich). Once the engine was warmed up, I had no adverse affects from the failed MAP sensor. However, my engine oil would become saturated with gas and my spark plugs would get coated with carbon.

It appeared that the main culprit was a bad design (I tried high and low quantity replacement parts) and the location of the sensor in the engine compartment.