Nissan Repair: nissan xterra engine codes, mass air flow sensor, mass air flow

Question
I just put a new air filter in my truck and the engine light when out.whats does this mean? It seems too good to be true.
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Followup To

Question -
I have a 2002 Nissan Xterra and my check engine light came on after i hit a big puddle last time it rained. I went to Auto Zone and they ran my codes and came up with, P0103; mass air flow input is higher then expected for the current engine operating conditions. The second code was, P0328; the voltage signal from knock sensor 1 is too high for the current engine operating conditions. Does this sound bad and what do you think it would take to fix it.

Answer -
Greg,

I know it sucks but you need to replace the knock sensor and the mass air flow sensor.  Then, reset the codes and you should be fine.  rockauto.com or courtseynissan.com are two good sources for on line parts.  If you are in a hurry check your local parts house.

Answer
Greg,

If the sensor got wet and now it is dry you might get lucky and the light will stay off.  The mass air flow sensor got wet.  The scary part is that the knock sensor was throwing a code.  That would mean that water splashed on it or worse the engine acutally ingested water and could not retard the engine enough and that set the code.  Whatever, if the light went out and the car is running properly count your blessings.