So my 99 Seville started felling sluggish yesterday. When I got gas the pump sounded kind of funny. But the car was fine for about half a tank of gas. Then it just started to fell funny sluggish and not as responsive.

I checked the codes and got PCM P0300 - Engine Misfire Detected

The car just had all new plugs and new wires almost a month ago and it has ran amazing since then. I still went back and checked them. So I am thinking maybe bad gas?

I went to autozone and got some sea foam and put it in there and filled up again. Still kind of sluggish..

Do you think it's just bad gas and what can I do to fix it other then sea foam? Thats about the only thing I can think of or that really changed.

 

Could a Mass Air Flow Sensor cause this?