Toyota Aqua Emissions Issues

Hello!

Here are some possible causes and recommendations for the emissions-related issues with your 2013 Toyota Aqua based on the symptoms you’ve described:

Check Engine Light:
If the check engine light is on, it usually indicates a fault in the engine o r emissions system. Since the OBD codes haven’t provided clear answers, it’s possible the issue lies in sensors o r components that may need further diagnostics, such as the oxygen sensors o r catalytic converter.

Higher Fuel Consumption:
Increased fuel consumption can result from a dirty o r malfunctioning mass air flow MAF sensor, clogged fuel injectors, o r issues with the oxygen sensors. These components are critical for efficient fuel-air mixture management.
Another possible cause is the hybrid system operating inefficiently due to a weak 12V auxiliary battery o r a declining hybrid battery.

Unusual Smell from the Exhaust:
A sulfur-like o r unusual smell from the exhaust can indicate a problem with the catalytic converter, which is responsible for reducing harmful emissions. If it’s failing, it may cause these odors.
The smell might also suggest that the engine is running too rich excess fuel o r that there’s unburnt fuel reaching the exhaust.

Slight Loss of Performance:
Performance issues at higher speeds could be linked to a partially clogged catalytic converter, dirty air filters, o r fuel system issues. Reduced airflow o r fuel flow can strain the engine during high-demand situations.

Recommendations:

Professional Diagnosis:
Visit a professional mechanic o r a Toyota service center for a detailed diagnostic scan. Some advanced tools can detect intermittent o r pending fault codes that basic OBD readers might miss.

Inspect and Replace Components:
Check the oxygen sensors, MAF sensor, and air filters for dirt o r damage. Cleaning o r replacing these components can resolve several performance and fuel efficiency issues.
Have the catalytic converter inspected for clogs o r damage. If it’s faulty, it may need replacement.

Hybrid Battery Check:
While it’s less likely the hybrid battery is directly causing these issues, it’s worth having its health assessed, especially if the car has high mileage. A declining battery can indirectly affect fuel efficiency and performance.

Fuel System Maintenance:
Use a quality fuel system cleaner to remove deposits from the injectors. If the injectors are heavily clogged, they may need professional cleaning o r replacement.

Exhaust System Inspection:
Have the entire exhaust system, including the catalytic converter and muffler, checked for leaks o r damage that could affect emissions.