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P174BModerateFuel System

P174B: Fuel Trim Cylinder Balance Bank 1

1 vehicles · 1 makes · $2,500-$9,000 repair

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P174B is an OBD-II diagnostic trouble code meaning “Fuel Trim Cylinder Balance Bank 1.” Individual cylinder fuel trim on Bank 1 is out of acceptable range. One cylinder is running differently from the others. This code appears across 1 vehicle models from 1 manufacturers, with repair costs ranging from $2,500 to $9,000.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (1)
  • Related Codes
  • FAQ
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Common Causes

1Leaking fuel injector
2Intake manifold leak at one cylinder
3Compression issue in one cylinder
4Valve train fault
5Carbon buildup on intake valve

Typical Repair Cost

$2,500 - $9,000

Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose P174B, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).

  • Read & clear engine codes
  • View freeze frame data
  • I/M readiness status
  • No batteries or app needed
Check Price on Amazon
Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

  • Enhanced diagnostics (ABS, SRS, transmission)
  • Repair Reports with verified fixes
  • Smog check readiness
  • Free app (iOS & Android)
Check Price on Amazon
Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

by LAUNCH

A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • Engine, transmission, ABS, SRS diagnostics
  • Live data stream & graphing
  • AutoVIN for vehicle identification
  • Free lifetime updates via Wi-Fi
Check Price on Amazon
Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

  • All-system diagnostics (25+ modules)
  • Bi-directional control & active tests
  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
Check Price on Amazon

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (1)

SQ5Critical

S-tronic (DL501/0B5) Mechatronic Unit Failure

2014-2017$2,500-$9,0000 reports

Related Codes (8)

P1740Torque Converter Clutch System Fault (Manufacturer Specific)P1744Torque Converter Clutch System PerformanceP174FFuel Trim Cylinder Balance Bank 2P0087Fuel Rail/System Pressure - Too LowP0088Fuel Rail/System Pressure - Too HighP0130O2 Sensor Circuit Malfunction (Bank 1, Sensor 1)P0131O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)P0135O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

FAQ

What does P174B mean?

P174B stands for "Fuel Trim Cylinder Balance Bank 1." Individual cylinder fuel trim on Bank 1 is out of acceptable range. One cylinder is running differently from the others.

What are the most common causes of P174B?

The most common causes of P174B are: Leaking fuel injector, Intake manifold leak at one cylinder, Compression issue in one cylinder, Valve train fault, Carbon buildup on intake valve. The specific cause varies by vehicle.

How much does it cost to fix P174B?

Repair costs for P174B range from $2,500 to $9,000, depending on the vehicle and root cause.

Which vehicles are affected by P174B?

Au7o has documented P174B across 1 vehicle models from 1 manufacturers: Audi.

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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