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Rotten egg smell
Medium — fix within days
You smell rotten eggs or sulfur coming from the exhaust, especially when you accelerate. The smell is sharp and hard to miss.
Possible causes
- Failing catalytic converter — Most likely · Codes: P0420P0430
Check first: Notice if the smell is strongest at the tailpipe and the check engine light is on. A bad converter cannot clean the exhaust properly. - Engine running too rich — Possible · Codes: P0172P0175
Check first: Look for black smoke from the exhaust and worse fuel economy. Too much fuel in the mixture makes the sulfur smell. - High-sulfur fuel — Less likely
Check first: Think about your last fill-up. If the smell started right after fueling at a new station, the fuel itself may be the cause.
Questions, answered
What usually causes this?
The most likely causes are: Failing catalytic converter; Engine running too rich; High-sulfur fuel. 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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