Audi DTC P1129 – Long Term Fuel Trim multiplier, Bank2 System too Rich
DTC P1129 meaning on Audi
The Diagnostic Trouble Code (DTC) P1129 on an Audi indicates that the Long Term Fuel Trim multiplier for Bank 2 is reporting a system that is too rich. This means that the engine control module (ECM) is detecting that the air-fuel mixture in the Bank 2 cylinders is too fuel-rich, leading to potential performance and emissions issues.
Audi DTC P1129 symptoms
Symptoms of DTC P1129 on an Audi may include:
- Decreased fuel efficiency
- Engine running rough or misfiring
- Check Engine Light (CEL) illuminated on the dashboard
- Strong fuel odor from the exhaust
Audi DTC P1129 causes
Common causes of DTC P1129 on an Audi include:
- Faulty oxygen sensor
- Leaking fuel injectors
- Dirty or clogged air filter
- Issues with the fuel pressure regulator
Audi DTC P1129 seriousness
While DTC P1129 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions. Ignoring this code can potentially cause damage to the catalytic converter and other engine components over time.
How to diagnose DTC P1129 on Audi
To diagnose DTC P1129 on an Audi, a mechanic may perform the following steps:
- Use a diagnostic scanner to retrieve the fault codes and freeze frame data
- Inspect the oxygen sensor readings for Bank 2
- Check for any fuel leaks or injector issues
- Inspect the air filter and intake system for any restrictions
How to fix DTC P1129 on Audi
To fix DTC P1129 on an Audi, the following steps may be taken:
- Replace the faulty oxygen sensor
- Clean or replace clogged fuel injectors
- Replace the air filter if dirty
- Check and adjust the fuel pressure regulator
How to erase DTC P1129 on Audi
To erase DTC P1129 on an Audi, the fault codes can be cleared using a diagnostic scanner. After fixing the underlying issue causing the rich condition in Bank 2, the codes can be cleared to reset the Check Engine Light and monitor the system for any recurring issues.
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.