P0175 on GMC: How to Diagnose & Fix
System Too Rich (Bank 2)
1 GMC model · 1 documented issue · $80-$250 repair
P0175 on GMC by model: symptoms, diagnosis and fix
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)
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 GMC?
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 GMC it is documented across 1 model: Jimmy.
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 GMC?
Published repair estimates on GMC range from $80 to $250 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.