2004 Toyota Prius, ~305K miles.
I got the check engine light come with the P0301, P0302, and P0300 codes.
I figured I should change the spark plugs since I haven’t changed them in forever. TBH, that was just a wild guess with little data. But I didn’t change anything out.
I reset the codes just to verify. The codes never came back in FOUR months so far.
How should I proceed? Wait it out? Do something? The car is performing fine otherwise, and no outward symptoms.
My guess would be failing coil packs. And spark plugs. If these plugs have over 300K miles on them, you know they must be shot or close to it. The best plugs are only good for about 100K miles maximum.
If you haven't had a misfire in four months, then it was just a temporary issue. Fuel contamination or something.
GTK. Thanks.