What does ignition coil "d" mean?

Question

I replaced the spark plugs on my 2004 Jeep Liberty now it has a miss, with codes p0300,p0304 and p2311.Replaced them before and had no problems.

Answer 1

Hi there,

Ignition coil D means the #4 ignition coil is showing a problem. This goes along with the misfire code P0304, which is for the #4 cylinder. The P0300 is a random misfire code, But I think it would be safe to replace the #4 ignition coil to solve the problem