P0174 is the Bank 2 equivalent of P0171. The engine's air-fuel mixture on Bank 2 has too much air or not enough fuel. The ECU detected that it cannot add enough fuel to maintain the correct 14.7:1 ratio, exceeding its positive fuel trim correction range.
DTC/P0174·BMW
P0174 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)BMW
P0174 on a BMW is the Bank 2 equivalent of P0171. The engine's air-fuel mixture on Bank 2 has too much air or not enough fuel. The ECU detected that it cannot add enough fuel to maintain the correct 14.7:1 ratio, exceeding its positive fuel trim correction range.
Repair cost on BMW€42 - €980
What does P0174 mean on a BMW?
BMW 3 Series
2006-2024BMW inline-6 engines (N52, N55, B58) are single-bank and won't produce P0174. The V8 S65 (E90 M3) and older V8 models will. On the S65, Bank 2 throttle body vacuum leaks and VANOS issues are the primary P0174 triggers.
What causes P0174 on a BMW?
Beyond the generic causes listed on the main P0174 page, these are the BMW-specific patterns we see most often:
BMW 3 SeriesBank 2 throttle body vacuum leak on S65 V8 (E90 M3)
BMW 3 SeriesVANOS issues causing lean condition on V8 models
How to diagnose P0174 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0174:
- Check if P0171 is also present. Both codes together means a whole-engine cause (MAF, fuel pressure, large vacuum leak), not a Bank 2-specific issue
- Check short-term and long-term fuel trims on Bank 2 with a scan tool. LTFT above +15% confirms lean on that bank
- Perform a smoke test or spray method around Bank 2 intake manifold gaskets and vacuum hoses
- Inspect and clean the MAF sensor with dedicated MAF cleaner
- Check fuel pressure at the rail with a gauge against manufacturer specification
- Check for exhaust leaks before the Bank 2 upstream O2 sensor
How much does P0174 cost to fix on a BMW? (EUR)
Estimated repair costs on a BMW (BMW parts and labour typically run 40% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0174 on BMW
These codes commonly cluster with P0174 on BMW vehicles:
FAQ: P0174 on BMW
What is the difference between P0171 and P0174?
Same problem, different engine banks. P0171 is Bank 1 (cylinder 1 side). P0174 is Bank 2. Four-cylinder engines only trigger P0171. P0174 appears on V6, V8, and boxer engines.
What does it mean if I have both P0171 and P0174?
Both banks lean simultaneously almost always points to a shared cause: dirty MAF sensor, low fuel pressure, failing fuel pump, or large vacuum leak on the intake manifold.
Can I drive with P0174?
Yes, for short distances. Avoid heavy load and high RPM. Lean conditions increase combustion temperatures, which can damage catalytic converters and exhaust valves. Fix within a couple of weeks.
How much does it cost to fix P0174?
From nearly free (cleaning MAF, replacing air filter, tightening a vacuum hose) to 300-500 euros for fuel pump or pressure regulator. Most common fixes are under 100 euros.
Looking for the full P0174 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0174 guideSkanyx · BMW
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