P0307 is a Misfire on Cylinder #7. Replace the spark plugs first if they are original, and clear the code. If it pops up again, then the ignition coil might be suspect or the fuel injector. Don't continue to drive it, as with any misfire unburnt fuel will migrate to the catalytic convertors and over time clog them up.
also something as simple as an intake air leak can cause the code too. and even a dirty fuel injector.
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