I have a 2008 Fit with 117K miles. I have p300-304 (random misfire, misfire cyl 1,2,3,4). It has a clear misfire at idle and does not accelerate at all. The engine will rev, but has no power. Sometimes the pedal will go all the way to the floor and it will still not go more than 20 miles an hour. There does seem to be some slight improvement when I used some Seafoam in the tank. All four plugs have been replaced since the issue began, with no change. Any ideas?

 

Just curious if the 4 misfire codes started flashing just after you put fuel in the car?.
If you've had the car for a while and know it's history. If it's been running ok and then it's missing on all 4 cylinders, it sounds like a case of bad gas. That's confirmed by it running better after adding seafoam to the tank.

 

Have you read the codes? Might tell you a lot. Clay