I got the engine code P0300 on my 1998 Nissan Altima 2.4L. When the engine is cold there is no problem. When warm the engine boggs down upon acceleration. The engine has stopped at a light, with A/C running. It surges between 1500 to 2000 RPM. It seems to act like the old carburetor engines, when there was a problem with the float, as in flooding.