Car is 02 wrx. Used ngk bkr7e's and they are gaped properly. I drove for the car around for like an hour and everything seemed fine. Check engine light started blinking and then stayed on. Im now getting p0301-p03049(misfire on all 4 cylinders) Car ran perfect on the way home after the light came on. Any ideas? Didnt have any problems before I changed the plugs either.

 

posibly damaged plug wires due to spark plug replacement.

 

Me personally I would reset the code and see if it comes back. maybe it wasnt used to a set of new plugs. not sure. sure fabric8 will be able to say.

 

Reset the ECU to erase any long- and short-term trim parameters and see if it comes back.. A misfire on all cylinders is strange because of the coil packs; there aren't a lot of things that can affect all cylinders when the each cylinder has its own coil.

I had a completely random misfire like that (but only 2 cylinders) when my 04 WRX had about 8k miles on it. That was the only time it ever happened, and that was about 6 years and 50k miles ago.

 

more than likely didnt push the spark plug wires all the way down (assuming they are plug wires,not coil packs).

try pushing them in until you feel a click.

let me know