I installed a CAI and since then i'm getting a missfire code 1399. Not sure in its just a coinsidence. I already changed out the plugs and it didnt fix it. My next thought is it could be a bad coil. Is there any way to check which coil could be bad or could it be something else? I dont want to buy new coils and still have the problem. Any ideas?

 

Have you tried putting the stock setup back just to see? Also, it usually gives you which cylinder the misfire is coming from.

only one CEL?

Have you reseted your ecu after the intake change?

 

Buying a spare coil is not a waste of money.
Do you know how much trouble a misfire in a modern engine of today?

Do yourself a favor...buy one!

 

Let it run long enough to set a permanent P0301-304 to determine what cylinder is misfiring.

 

I have reset the ecu. It comes on under hard acceration about 6k it will flash and if you stay on it then it stays on. I will see if it throws another code. I dont mind buying one coil but i'm not sure which one is bad