P0175 on Audi: How to Diagnose & Fix
System Too Rich (Bank 2)
1 Audi model · 1 documented issue
P0175 on Audi by model: symptoms, diagnosis and fix
Audi TSB 2046724/5 covers sporadic warm-engine no-start or long cranking after the vehicle sits without fully cooling. A rich-mixture DTC may occur, but often there is no DTC. Audi’s procedure distinguishes fuel in the oil from a short-trip profile, ECM software, high-pressure injector leakage and high-pressure fuel-pump leakage rather than assuming one failed component.
Common Symptoms
- Warm-soak no-start with normal starter operation
- Long cranking followed by rough running for a few seconds
How to Fix
Have the dealer read DTCs and ODIS fuel-in-oil value, verify ECM software and perform Audi’s high- and low-pressure holding tests. If high-pressure behavior is abnormal, borescope the combustion chamber to identify a leaking injector. If low-side pressure builds correctly but drops more than 1.5 bar in the first 15 minutes, Audi says at least one HPFP may be leaking and directs replacement of both pumps plus an oil change. Select no pump or injector until the test identifies the path.
Owner tips & cautions
- TipRecord engine temperature and how long the car sat before the hard start; do not approve pumps or injectors without the pressure-hold results.
Sources for this issue (1)
P0175 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0175 mean on a Audi?
P0175 stands for "System Too Rich (Bank 2)." P0175 is a generic OBD-II code meaning the engine computer detected that the air-fuel mixture on bank 2 is too rich, with too much fuel relative to air. The computer has had to remove fuel (negative fuel trim) to try to correct it but has reached its adjustment limit. Bank 2 is the cylinder bank that does not contain cylinder #1. A persistently rich mixture wastes fuel, causes rough running, and can overheat and damage the catalytic converter over time. On Audi it is documented across 1 model: S8.
What are the most common causes of P0175?
The most common causes of P0175 are: Dirty or faulty mass air flow (MAF) sensor, Leaking or stuck-open fuel injector, Excessive fuel pressure / faulty fuel pressure regulator, Faulty or contaminated oxygen sensor, Engine vacuum leak or false air reading, Dirty/clogged air filter or restricted intake, Leaking fuel injector O-rings or fuel saturation, Faulty coolant temperature sensor skewing fuel trims. The specific cause varies by vehicle.
How much does it cost to fix P0175 on a Audi?
Repair costs vary widely with the root cause and Audi model; each issue on this page carries its own estimate where one is published.
Looking for P0175 on a different make?
View P0175 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.