Can a faulty ignition coil be mistaken for a spark plug issue in a Prius?

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Can a faulty ignition coil be mistaken for a spark plug issue in a Prius?

Sometimes, ignition coils fail alongside spark plugs, causing similar symptoms like misfires and poor acceleration. How can Prius owners differentiate between a bad ignition coil and worn-out spark plugs?

Zarnish asked on 14 Feb 2025 16:33:22 pm

1 Answer

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Car Mechanic Expert - on 14 Feb 2025 16:45:11 pm

Yes, a faulty ignition coil can cause symptoms that are similar to spark plug problems:

Both misfires and poor acceleration can occur with a bad ignition coil o r worn spark plugs.
Ignition coils are responsible for delivering electrical current to the spark plugs, and if they fail, it can lead to misfires.

How to differentiate:

If the problem is isolated to a specific cylinder, it could be a faulty ignition coil.
If all the plugs are bad o r have visible wear, it’s more likely the spark plugs themselves.

Best practice: If you notice misfires, it’s often best to inspect both the ignition coils and spark plugs to rule out both issues.