P1174 On Chevrolet and Saturn, fuel trim shows a cylinder balance problem on bank 1

Fuel trim cylinder balance, bank 1

Severity not verified — if the car runs badly, have it inspected

The GM bulletins tie it to injector concerns and driveability symptoms, but none we read rates how urgent it is.

It gets more serious if:

  • Inspect soon: Get it inspected soon if the engine misfires, hesitates or loses power.

Source: how we rate severity

P1174 in short

On Chevrolet and Saturn, P1174 is fuel trim cylinder balance for bank 1: the computer sees the cylinders on that bank not running evenly. Clogged or weak fuel injectors are a common cause, followed by a vacuum leak or ignition fault. GM bulletins cover injector testing.

The computer adds or removes fuel to keep the mixture right. P1174 on these GM vehicles flags that bank 1 is not balanced, so one or more cylinders is running richer or leaner than the rest.

GM preliminary bulletin PIP4017C tells dealers to test the injectors with the Active Fuel Injector tool on Malibu, G6, Solstice, Sky, Vue and Aura, and GM bulletin 070604027 covers clogged injectors on 5.3L trucks.

A Tahoe owner thread traced the code to a disconnected spark plug wire, so ignition checks are worth doing first.

Pick your make

P1174 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Clogged or weak fuel injectors on bank 1

    Supported by vehicle data
    Why it ranks here
    Both GM bulletins tie P1174 to injector concerns and a Chevrolet truck forum names injectors as a common cause.
    What would change this
    Rises if an injector balance test shows uneven flow. Falls if all injectors flow equally.
    How to test the fuel injector

  2. Oxygen sensor or MAF sensor error, or a vacuum leak

    Common general cause
    Why it ranks here
    Chevrolet truck guidance lists the O2 sensor, MAF and vacuum leaks among common causes of trim code P1174.
    What would change this
    Rises if fuel trims are skewed and sensor readings look off. Falls if readings are normal.
    How to test the oxygen (o2) sensor

  3. Ignition fault on one cylinder, such as a loose spark plug wire

    Possible — needs testing
    Why it ranks here
    An owner thread on a Tahoe found a disconnected spark plug wire behind the code, which is weak evidence but cheap to check.
    What would change this
    Rises if a plug wire or coil is loose or worn. Falls if ignition is sound.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes and check bank 1 fuel trims. Note P1175 or misfire codes stored with P1174.

    Low riskTool: OBD-II scan tool

  2. With the engine off, check spark plug wires, coil connectors and vacuum hoses on bank 1.

    Low risk

  3. Have the injectors tested for balance with the GM injector tester.

    Best left to a shopTool: GM Active Fuel Injector Tester

    Warning:Injectors are under fuel pressure. Let a shop do it.

Symptoms

  • Check engine light
  • Hesitation, rough idle or misfire
  • Reduced power Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on

How to fix

  1. With the engine off, check that spark plug wires and coil connectors are fully seated.

  2. Check vacuum hoses on the intake for cracks or disconnected ends.

Parts and cost context

  • Fuel injector:Test before replacing. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chevrolet

  • 2006–2007 · Malibu

    Supported by vehicle data

    GM bulletin PIP4017C tells dealers to test injectors for P1174 on the 2006 to 2007 Malibu.

  • 2007–2008 · Tahoe

    Supported by vehicle data

    GM bulletin 070604027 covers clogged injectors on 5.3L Tahoe, Suburban and Silverado with P1174 and P1175.

  • PIP4017CStatus unverified

    Fuel injector concern that could set P1174

    2006–2007malibu · issued · NHTSA 10161013

    GM preliminary information telling dealers to test the fuel injectors with the Active Fuel Injector Tester tool when P1174 is set. Also lists Pontiac G6 and Solstice and Saturn Sky, Vue and Aura.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 070604027Status unverified

    5.3L driveability symptoms and clogged injectors with P1174 and P1175

    2007–2008tahoe, suburban, silverado-1500 · issued · NHTSA 10023215

    Covers hesitation, misfire and lack of power on 5.3L engines from clogged fuel injectors, with fuel trim and cylinder balance codes including P1174 and P1175.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Saturn

  • PIP4017CStatus unverified

    Fuel injector concern that could set P1174

    2006–2007malibu · issued · NHTSA 10161013

    GM preliminary information telling dealers to test the fuel injectors with the Active Fuel Injector Tester tool when P1174 is set. Also lists Pontiac G6 and Solstice and Saturn Sky, Vue and Aura.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0171Engine computer has reached its limit adding fuel on bank 1: the mixture is lean

    Shares causes Supported by vehicle data

    GM bulletin 070604027 lists lean and rich trim codes with P1174 for clogged injectors.

  • P0300Random or multiple-cylinder misfire detected

    Shares causes Supported by vehicle data

    The same bulletin lists P0300 with P1174 for injector-related misfire.

All Fuel trim (air-fuel mixture) codes

P1174 questions

Is P1174 the same on all cars?

No. It is manufacturer-specific. On Chevrolet and Saturn it is fuel trim cylinder balance for bank 1.

Sources and review

  1. Chevrolet 070604027: 5.3L driveability symptoms and clogged injectors with P1174 and P1175 — NHTSA manufacturer communications ,
  2. Chevrolet PIP4017C: Fuel injector concern that could set P1174 — NHTSA manufacturer communications ,
  3. P1174 fuel trim cylinder balance bank 1 — ChevyTrucks.org
  4. P1174 trouble code explanation — TroubleCodes.net
  5. DTC P1174 fuel trim cylinder balance (forum thread) — Tahoe Yukon Forum
Last reviewed
Written by
Saurabh K.
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