Terrible engine sound prius 2008 (fault code: P0304)

Sorry I missed this. I tried plugs, coils, fuel cleaner, but then I saw this video and it matched what mine sounded like and it said ti was just a bad injector. I bought 4 refurbished injectors for about $40ish and it fixed my rattle/misfire problem.

 

I'm currently experiencing the same issue and I hope it's not a blown head gasket. I'm not losing any coolant and I don't see any leaks so I don't think it could be but the symptoms is so strange because I only encounter this issue when the car is sitting "hot" for like 20-30 minutes.

 

Just want to say thank you to the great PriusChat community and this thread in particular. Last week my 2006 Gen 2 started running rough about 100 miles from home. I have an OBDII bluetooth reader plugged in my port and pulled the codes P0138 (O2 Sensor Circuit High Voltage), P0304 Cylinder 4 Misfire), and P0171 (System Too Lean). I made the call that I could limp home, running cautiously, and did so without problem. Jumped on PriusChat the next morning and decided that it was likely the ignition coil on cylinder #4. Ordered a new Denso Coil and since I haven't replaced the plugs ever, ordered a set of new NGK Iridiums. Put them in today and car is back in tip-top shape. Wanted to document the codes and fix to pay it forward. Thanks all!