P0174 on Chevrolet vehicles
Fuel System Too Lean (Bank 2) — what it means on a Chevrolet, whether it's safe to drive, and the fixes by model and year.
P0174 on a Chevrolet means fuel system too lean (bank 2). Most vehicles stay drivable short-term, but diagnose it promptly. The most common cause is vacuum leak specific to bank 2 (intake gasket, vacuum tee, brake-booster tee) (typically $80–$600). Pick your Chevrolet model below for its known failure patterns, recalls, and TSBs.
What does P0174 mean on a Chevrolet?
P0174 is the Bank 2 counterpart of P0171. It is set when the engine control module sees long-term fuel trim on Bank 2 driven beyond approximately +25 %. The ECM is adding the maximum allowed amount of fuel and the Bank 2 oxygen sensor still reports lean. Because P0174 only applies to V-engines and engines with separate exhaust banks, whether P0174 appears alongside P0171 tells you a lot about the root cause.
P0174 is a standardized OBD-II code, so its definition is the same on every Chevrolet. What differs by model and engine is which cause is most likely — pick your Chevrolet model below for a diagnosis tuned to its known failure patterns, recalls, and TSBs.
Is it safe to drive a Chevrolet with P0174?
In most cases a Chevrolet stays drivable for short trips with P0174 active, but diagnose and repair it promptly. This is a moderate-severity code — ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.
What causes P0174 on a Chevrolet?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Vacuum leak specific to Bank 2 (intake gasket, vacuum tee, brake-booster tee) | Most common | $80–$600 |
| Cracked plastic intake manifold on V-engines (common on Ford and Chrysler V6/V8s) | Common | $250–$900 |
| Bank 2 fuel injectors clogged or under-delivering | Common | $150–$1,200 |
| Bank 2 upstream O2 sensor lazy or biased lean | Common | $150–$450 |
| Bank 2 exhaust leak upstream of the front O2 sensor | Occasional | $100–$500 |
| Weak fuel pump or clogged filter (both banks lean — P0171 also present) | Occasional | $80–$900 |
| PCV system fault drawing extra air into Bank 2 | Occasional | $30–$200 |
Repair costs are typical US ranges and vary by Chevrolet model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.
P0174 by Chevrolet model
Select your Chevrolet model and year for a P0174 diagnosis tuned to that vehicle's failure patterns, recalls, and TSBs.
Chevrolet Silverado 1500
1,648 NHTSA owner complaints · 14 recalls on record across the years covered below.
Chevrolet Equinox
1,100 NHTSA owner complaints · 8 recalls on record across the years covered below.
Chevrolet Tahoe
518 NHTSA owner complaints · 11 recalls on record across the years covered below.
Chevrolet Malibu
1,697 NHTSA owner complaints · 8 recalls on record across the years covered below.
Chevrolet Traverse
795 NHTSA owner complaints · 9 recalls on record across the years covered below.
Chevrolet Trax
117 NHTSA owner complaints · 3 recalls on record across the years covered below.
Complaint and recall counts are NHTSA totals for the model years covered on this site, not counts specific to P0174.
P0174 on other makes
Other codes on Chevrolet vehicles
P0174 on a Chevrolet: frequently asked questions
What does diagnostic trouble code P0174 mean on a Chevrolet?
P0174 is the Bank 2 counterpart of P0171. It is set when the engine control module sees long-term fuel trim on Bank 2 driven beyond approximately +25 %. The ECM is adding the maximum allowed amount of fuel and the Bank 2 oxygen sensor still reports lean. Because P0174 only applies to V-engines and engines with separate exhaust banks, whether P0174 appears alongside P0171 tells you a lot about the root cause. P0174 is a standardized OBD-II code, so the definition is the same on every Chevrolet — which cause is most likely varies by model and engine.
What are the symptoms of P0174 on a Chevrolet?
Check Engine Light is illuminated. Rough idle, especially when cold. Hesitation or stumble on light acceleration. Reduced fuel economy. Mild power loss. Possible whistling vacuum-leak sound
What causes P0174 on a Chevrolet?
Vacuum leak specific to Bank 2 (intake gasket, vacuum tee, brake-booster tee) (most-common). Cracked plastic intake manifold on V-engines (common on Ford and Chrysler V6/V8s) (common). Bank 2 fuel injectors clogged or under-delivering (common). Bank 2 upstream O2 sensor lazy or biased lean (common). Bank 2 exhaust leak upstream of the front O2 sensor (occasional). Weak fuel pump or clogged filter (both banks lean — P0171 also present) (occasional). PCV system fault drawing extra air into Bank 2 (occasional)
Is it safe to drive a Chevrolet with P0174?
In most cases a Chevrolet stays drivable for short trips with P0174 active, but it should be diagnosed and repaired promptly — this is a moderate-severity code. Ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.