Hello all,

I have a 2012 Nissan Sentra SR with 144,000 miles on it and when I started the car, the “Service Engine Soon” light came on. I scanned it for codes and it shows P0304 & P0304P. Not sure if this is the same thing? After googling fixes, it looks like it can possibly be the spark plugs or the ignition coils. But the strange thing is that the light only popped up when I started the car after sitting for a day. I don’t recall seeing it prior when I was driving or feel any issues with it. I also replaced the spark plugs roughly 10,000 miles ago with NGK lx iridium plugs, but I didn’t replace the coils. Should I just replace both the plugs and coils, and hope that clears it? Any advice would greatly be appreciated, and I would like to try to fix it myself instead of taking it to the mechanic so I can learn and save some money. Thank you.