Check Engine Light keeps turning back on

have a Toyota Corolla2009 S and changed all coils and sparkplugs and check engine light comes on with same misfire codes

Went to the mechanic to fix it and he told me i needed all sparkplugs and coils changed, after 2 days that i changed them, check engine light came on with the same misfire codes.

well, bad fuel injectors can cause misfires, as can leaking intake manifold gaskets or head gasket, or weak fuel pump. but really, he charged you enough make him fix it free now or return your money and go to a better mechanic

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