So i am now back to this damn P0303 code. What could be causing my 3rd cylinder to be misfiring? I have new ngk's for plugs (less than 1k miles on them) and new plug wires, and new injectors. what could be causing this code? I also have a P1684, which to my understanding is the battery has been disconnected in the last 50 starts. SO if thats the case, the p1684 shouldnt come back once i clear it? usually i clear my codes by disconnecting the engative battery terminal, but i read somewhere its not smart to do it that way and it will always trigger the p1684 code???? some insight ont his theory?

 

try switching the #3 plug with the #1 see if the code follows it to that cylinder. I had the same problem come to find out it was a bad plug.... and it happens. they can look good on the outside but the porcelin can crack unde the metal.. its a quick easy and a free check.. unless you need to fork over 5 bucks for a new plug.

 

I have switched plugs around, as well as switched the number 2 and number 3 wires, but every time i clear the codes, it goes back to cylinder 3 still...I've been told it could be a weak spot on my coil pack, but i thought once it starts going it'll be one side, (as in 1/2 or 3/4) not just a single cylinder