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Q: Check Engine Light keeps appearing, trouble code changed

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The first time check engine light went on the code was 302 and 304 we changed all the spark plugs and 1 of the coils. The second time the CEL came on it said 302 so we switched the spark plug and coil to position 1 to see if somehow it was faulty. Now the check engine light is on again and throw code 300 only. So i am guess that it is something else....should i pay for dianostic at this point or should i try something else?

My car has 140000 miles.
My car has an automatic transmission.

Hi there, thanks for writing in. Having a professional mechanic complete a diagnostic inspection to determine why a mechanical part failure continues to happen is always the best course of action; especially if you’re frequently replacing spark plugs on a 2010 Prius Hybrid. To avoid any unnecessary repairs, I would highly suggest contacting one of our local mechanics and ask them to complete a Check Engine Light inspection. This will allow them to pinpoint the source of the issues you’re having; before spending more money on replacement parts.

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