my 2001 honda crv is about to turn 150K started idling very rough..why?

i have presently this problem at 157 km, do you have a chek engine? Is this possible, a problem caused by oxygen sensor or kind like mixed ratio gaz/oil ? The sendor not doing is job, so the mix is too rich, too many gasoline is sent... see website about oxygen sensor http://www.aa1car.com/library/o2sensor.htm Also, a first try can be by changing your gaz filter, it's not expensive, and it's normal to change it regularly, it's only 20$ + the time