P0175: How to Diagnose & Fix — System Too Rich (Bank 2)
3 vehicles · 3 makes · $50-$500 repair
How to diagnose and fix P0175: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
GMC Jimmy · 1996–2001
The fuel pressure regulator diaphragm ruptures. Because the regulator is housed inside the intake on the 4.3L CSFI engine, raw fuel is dumped directly into the intake. Causes rich running, hard hot starts, and fuel smell. Can flood the engine with fuel.
Common Symptoms
- Hard starting when hot
- Strong fuel smell
- Black smoke from exhaust
- Fuel pooled in the intake around the regulator
How to Fix
Replace the fuel pressure regulator. On the 1996-2001 4.3L CSFI engine it is housed inside the intake with the main injector, so the upper intake plenum must be removed (aftermarket regulators and reconditioned injector assemblies cost less than the dealer assembly). Before removing the plenum, take off the manifold tuning valve on top of the intake and inspect the regulator area. Fuel lying in the intake, or an unusually clean area around the regulator, points to a leaking diaphragm. Replace the upper plenum gasket when reassembling.
Sources for this issue (2)
Kia Telluride · 2020–2025
The 3.8L Lambda II V6 in the Telluride experiences fuel dilution of the engine oil when driven primarily on short trips (under 10 miles). Fuel washes past the piston rings during cold starts and does not fully evaporate because the oil never reaches full operating temperature. The diluted oil has reduced viscosity and lubrication properties, accelerating engine wear. The issue is more pronounced in cold climates. Oil analysis shows fuel contamination levels of 3-5% in severe cases.
Common Symptoms
- Oil level rising above the full mark on dipstick
- Gasoline smell from engine oil on dipstick
- Oil appearing thinner than normal
- Oil change interval warning appearing early
- Increased engine noise from reduced oil film strength
How to Fix
Change oil more frequently if driving primarily short trips — every 3,000-4,000 miles instead of the 7,500-mile factory interval. Take the vehicle on a 20+ minute highway drive weekly to bring the oil to full operating temperature and boil off fuel contamination. Use a quality full-synthetic 5W-30 oil that resists fuel dilution better than conventional oil. Consider oil analysis testing (Blackstone Labs, $30) to monitor fuel dilution levels. If fuel dilution exceeds 5%, investigate injector spray patterns.
Sources for this issue (1)
Audi S8 · 2013–2018
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. Don't replace a pump or injector until the tests show which one is leaking.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
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)
Find P0175 by make
Browse every documented model and issue for your make.
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?
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.
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?
Repair costs for P0175 range from $50 to $500, depending on the vehicle and root cause.
Which vehicles are affected by P0175?
Au7o has documented P0175 across 3 vehicle models from 3 manufacturers: Audi, GMC, Kia.
Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.