Audi DTC P1125 – Long Term Fuel Trim Additional Air, Bank2 System too Rich
DTC P1125 meaning on Audi
The Diagnostic Trouble Code (DTC) P1125 on an Audi indicates that the Long Term Fuel Trim Additional Air, Bank 2 system is too rich. This means that the engine control module (ECM) has detected that the air-fuel mixture in the Bank 2 of the engine is running too rich over an extended period of time.
Audi DTC P1125 symptoms
Symptoms of DTC P1125 on an Audi may include:
- Decreased fuel efficiency
- Black smoke from the exhaust
- Rough idling or stalling
- Check Engine Light (CEL) illuminated on the dashboard
Audi DTC P1125 causes
Common causes of DTC P1125 on an Audi include:
- Faulty oxygen sensor
- Leaking fuel injectors
- Dirty or clogged air filter
- Issues with the Mass Airflow Sensor (MAF)
- Vacuum leaks
Audi DTC P1125 seriousness
Ignoring DTC P1125 on an Audi can lead to potential engine damage and decreased performance. Running too rich can cause excessive carbon buildup, damage the catalytic converter, and result in poor fuel economy.
How to diagnose DTC P1125 on Audi
To diagnose DTC P1125 on an Audi, a mechanic would typically perform the following steps:
- Use an OBD-II scanner to retrieve the fault codes
- Inspect the oxygen sensor readings
- Check for any vacuum leaks
- Test the fuel injectors for leaks or clogs
- Inspect the air filter and MAF sensor
How to fix DTC P1125 on Audi
To fix DTC P1125 on an Audi, the following steps may be taken:
- Replace the faulty oxygen sensor
- Clean or replace clogged air filters
- Repair any vacuum leaks
- Clean or replace fuel injectors if necessary
- Check and clean the MAF sensor
How to erase DTC P1125 on Audi
After fixing the underlying issue causing DTC P1125 on an Audi, the fault codes can be erased using an OBD-II scanner. This will reset the Check Engine Light and clear the DTC from the ECM’s memory.
Recommended tools for Audi diagnostics
Explore our expert picks: The Best OBD2 Scanners for 2025
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.