02 Maxima P0159
 

Just bought this car 2 weeks ago, finally got around to replacing the air filter yesterday evening. The old filter I pulled out was horrible, doesn't look like its been changed in 100k miles. Could it have thrown this code do to the new found air, and it just needs time to relearn?

O2 sensor going and air filter are generally unrelated. you have a lazy O2 sensor...time to swap it out.