Ok so I have an 2004 s40 t5, everything was going great and then car starts missing and running horrible. I checked the codes and replaced the plugs and coils. Car is back to running perfect and then 2 days later while driving, the car shutters and dies and won’t start back. I run the codes again and it says p0300 random multiple misfire, p0304 cylinder 4 misfire, p2306 ignition coil c primary control circuit low, p2303 ignition coil B primary control circuit low, and p0303 cylinder 3 misfire. Now my question is did I just get a part that failed in 2 days or is there a more underlying problem? Any help would be greatly appreciated.

 

how's the connections to the coils look? is the wiring harness in good shape or do you see any corrosion or cracks in the connectors?