Billmcse
New Member
Engine light came on about 2-3 months ago. Got a code of P0304 which is the 4th spark plug misfiring. I had replaced the plugs about 25,000 previously and the coils hadn't been changed before. So I went and bought both plugs and coils, swapped em all out and the hesitation went away. I had erased the code and the engine light stayed off since then. However, today the light came back on and the engine had some noticeable lag and hesitation. With the plugs and coils, what are the most other likely causes for a P0304 since the same code is now back?