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Check engine light on
Medium — fix within days
The check engine light on the dashboard stays on while you drive. The car may run fine, or it may feel rough, lose power, or use more fuel.
Possible causes
- Loose gas cap — Most likely · Codes: P0442P0455
Check first: Tighten the gas cap until it clicks, then drive a few days. A loose cap is the most common and cheapest cause. - Failing oxygen sensor — Possible · Codes: P0130P0131P0132
Check first: Notice your fuel economy. A sudden drop in miles per gallon, plus a rough idle, points to an oxygen sensor. - Bad catalytic converter — Possible · Codes: P0420P0430
Check first: Notice any rotten egg smell from the exhaust or a loss of power when you accelerate. Both point to the converter.
Questions, answered
What usually causes this?
The most likely causes are: Loose gas cap; Failing oxygen sensor; Bad catalytic converter. If you are not sure what is wrong, have it checked by a qualified technician.
Is it safe to drive with this symptom?
Drive with caution and book a check within days. Do not ignore it.
Not repair advice. If you are not sure what is wrong, have it checked by a qualified technician. Cars differ by make, model and year.
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