2001 pathfinder engine code

[vq35dePathfinderSE]

ive been have this problem with my 2001 pathfinder where the engine light is sometimes on (wet weather) and sometimes off (in mostly dry weather)....ive hooked it up to my scanner and it came up with a blank code i think the number was either p106 or p160 i looked up that code on my computer and it pulled up a oxy senser.......but if it is a oxy sensor then why would it give me a blank code? and why would it be intermidiate?

[Jack44]

DTC P0106 Manifold Absolute Pressure (MAP) System Performance

DTC P0106 Manifold Absolute Pressure (MAP) System Performance

They both came up?

[vq35dePathfinderSE]

no i dont think that was the code and only one came up i looked it up in mitchell and it gave me an o2 sensor (rear left)....but recently i had the truck on the hoist and found that the over axel pipe going from the front muffler to the rear muffler is broken (the weld) i was wonderin if this has anything to do with it