First car started to idle rough, got the code and put a used ignition coil on which fixed it. When replaced them I kept the old ones. Have not had the a/c off in many months in Florida. A few weeks ago if gas was slightly above 1/4 tank if you hit the throttle it would bog down like no fuel. Put a new fuel pump on. Then the car started to idle rough between 250rpm to about 600rpm and would put in neutral when stopped at a light. Check engine light came on P0133 which is bank 1 upstream o2 sensor. Replaced it and also put new spark plugs in. Erased code and did a relearn on ECM. The car still idles like it did before. I put a new Hitachi throttle body on 2 years ago. Could someone please give some help on what the problem could be. I have a feeling the check engine light will come on again showing P0133 like it has the other times. My old 02 sensor was a new Nissan when I changed it it had a white powder on it. I am lost.