Rotten Egg Smell During Acceleration
A rotten egg (sulfur) smell when accelerating in a 2020 Ford Mustang typically indicates a rich fuel mixture or a failing catalytic converter. The sulfur odor is caused by unburned fuel or excess sulfur in the exhaust, often due to a malfunctioning oxygen sensor, fuel system issue, or a catalytic converter that is not properly converting hydrogen sulfide.
Diagnosis Details
Possible Causes
Failing catalytic converter – internal damage or clogging prevents proper conversion of sulfur compounds.
Oxygen sensor malfunction (upstream or downstream) causing rich fuel mixture.
Fuel system issue (e.g., leaking injector, high fuel pressure, or contaminated fuel) leading to excess unburned fuel.
Engine misfire or ignition problem causing incomplete combustion.
Related OBD-II Codes
Not satisfied with this diagnosis?
Try Another DiagnosisWhat To Do Next
What You Should Do
Have the vehicle inspected by a qualified mechanic.
They should check for diagnostic trouble codes (DTCs), test the oxygen sensors, inspect the catalytic converter for damage or blockage, and evaluate fuel trim data.
If the catalytic converter is failing, replacement is often necessary.
Also consider using a different fuel brand to rule out fuel quality issues.
Related Repairs
Share this diagnosis
Help others with similar symptoms
Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
