I have a 07 Mazda 3 and it seems like ita getting worst by the day. I have a check engine light on with the code P2177 System too lean, I'm pretty sure its losing its power when accelerating. I'll be honest, I don't really know what a misfire is like, but I'm pretty sure it may be as the engine is running rough at the moment.
My biggest worry is the sound of the engine when putting my foot down on the gas. It seems to get worst and louder every day. The best way I can explain it, is that it sound like a rattle in the engine. I do have a video, it's the only one I could get. Please watch it.
Is this possible that the spark plugs need replacing? I have no idea what they were last changed.
It doesn't seem that loud, but it really is