Hello. My name is Mike. I need some severe help with my car. I have a 2012 Mazda 3, Very base model 2.0 non skyactive motor, 5spd A/T. This past Saturday, Coming home from work I developed a pretty severe misfire. Plugged it in and pulled 2 codes. P0300 and P0301. Random cylinder misfire and cylinder one missfire. Took the mass air flow sensor out and cleaned it. Changed the cylinder one coil pack and all spark plugs, Checked all the injectors the fuel pump pretty much everything that I would need to check. Car is still misfiring. Also did a compression test on all 4 cylinders and they are reading 90 across-the-board. Replaced the battery. Now since I replaced of the battery I no longer get a code for cylinder 1, now its cylinder 3. The car mainly only misfires under a load, it will occasionaly at idle but not nearly as much or bad. Even check the timing everything is all right. I am literally throwing my hands up with this car. I don't know what to do. Someone please help.

 

Did you replace all the sparkplugs?

 

Yes. That's what it says in the post.