I’ve changed my ignition coils and spark plugs 6 months ago, they have been excellent until now (I assume they are the issue.) I received the code P0302, cylinder 2 misfire, and decided to check ignition coils and spark plugs. Ignition coils seem great, spark plugs were recommended a change by professionals I asked for help from. So I replaced the plugs with original Prius 3rd gen spark plugs from the dealership. After replacing them, I left the car on idle to see if it would act up again or not charge the secondary engine. It worked and the check engine light disappeared on its own. So I assumed the problem was solved, but when I tried to cruise with it which I didn’t have to go over 5mph, I heard rattling/shaking and immediately turned the ignition off. After this I turned the ignition on, on idle, and the shaking/rattling was showing up slightly again. Now I readjusted everything and turned the ignition on, no rattling/shaking on startup, but I didn’t want to risk it because I’m not sure if I’ll damage the engine or anything that might be lead to damage. I haven’t been able to figure out what exactly the problem is. I read loads of articles, I know what might be causing it but I don’t see anything. Could be a fuel injector, but I am afraid of running the engine because im not sure if it’ll damage anything as I said. Thank you all in advance for your help and advice.
Surprisingly, placing everything back to where they were from the beginning, the vehicle didn’t have a problem running. Maybe I tightened the spark plugs better this morning. I’ll keep in touch through the post.
How confident are you that they weren't counterfeits? Was it running well shortly before you changed those parts?
