How To Repair Gm Code Co545

What Does Code P0171 Mean for Your GM Vehicle?

P0171 definition : Bank one has too much air or not plenty fuel
Event Severity: MODERATE– Extended driving with this code can cause internal engine damage.
Repair Urgency: Get this code fixed every bit soon equally possible to avoid damage to spark plugs, pistons, and catalytic converters.
Diagnosis: It is of import to complete the entire diagnostic procedure when diagnosing the P0171 code on your Full general Motors vehicle (Buick, Cadillac, Chevrolet, GMC, Saturn, Pontiac, HUMMER, and more than). Many people will replace the air-fuel sensor or oxygen sensor as shortly as they get a bad reading, but the root cause of the GM P0171 lawmaking tin can also be a dingy or faulty mass airflow sensor or vacuum leak, thus causing the O2 or MAF sensor to read differently to compensate.

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Combustion engines run almost efficiently when they maintain an air-fuel mixture ratio of 14.seven parts air to 1 part fuel. Also much fuel and/or too niggling air results in the engine running rich setting a P0172 trouble code, while too petty fuel and/or too much air results in the engine running lean resulting in a cheque engine calorie-free for the GM P0171 code. The lean condition can exist acquired by a vacuum leak, which introduces more than air into the air-fuel mixture, or by a weak fuel system, which does non input enough fuel into the air-fuel mixture. To keep the engine running properly, the powertrain control module (PCM) tries to recoup for the lean condition past injecting more fuel to the mixture in an effort to maintain the proper 14.seven:1 ratio. When these adjustments become too large, the GM P0171 code is triggered.

P0171 Causes

Faulty or muddy mass airflow sensor
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket.
Weak fuel pump
Clogged or dirty fuel injectors
Chock-full fuel filter
Exhaust leak
Faulty oxygen sensor
Faulty air-fuel ratio sensor

P0171 Symptoms

Check Engine Lite is on or flashing
Lack of power from the engine
Rough idle
Engine "coughing" or misfiring
Tip of spark plugs are white
Normally associated with error codes: P0174

How Exercise I Set up Code P0171?

With a GM P0171 lawmaking, the kickoff footstep is to get information technology properly diagnosed to figure out what is causing the engine to run lean. Using the live data function of the FIXD sensor and app allows you to read and analyze fuel trims to properly diagnose a P0171 code.

If your engine is running lean and yous're not comfortable diagnosing this issue at home, we recommend finding a RepairPal-certified store to pinpoint the problem and give an accurate guess for repairs.

These shops can not merely help you effigy out what'due south going incorrect before y'all waste time and coin on the incorrect parts, only they also offer a minimum 12-calendar month, 12,000-mile warranty and stand up behind all their estimates with guaranteed fair pricing.

> Find a RepairPal Certified Shop Near Y'all

How Much Does It Cost to Fix Lawmaking P0171?

If you have your machine to a shop for diagnosis, most shops volition offset with an 60 minutes of "diag time" (the time spent in labor diagnosing your specific issue). Depending on the shop's labor charge per unit, this typically costs somewhere between $75-$150. Many, if non most, shops will apply this diagnosis fee to any required repairs if you accept them perform the repairs for y'all. From there, a shop will be able to give you lot an accurate estimate for repairs to set your P0171 code.

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Possible Repair Costs for P0171

When it comes to making repairs associated with the GM P0171 code, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated price of repair includes the price of the relevant parts and the cost of labor required to make the repair.

Vacuum leak $100-$200
Clean MAF $100
Supersede MAF $300
Fuel Pump $1300-$1700
Fuel force per unit area regulator $200-$400
Exhaust repair $100-$200 (if welded to repair)
Air fuel sensor or oxygen sensor $200-$300

DIY Steps to Diagnose Code P0171

If you'd like to try to fix code P0171 at home without throwing money at parts, you'll want to follow the steps below for proper diagnosis. Proceed in mind this is an intermediate-level diagnosis and repair and not recommended for beginners. Diagnosis requires more specialized equipment beyond what the FIXD Sensor tin provide and it tin can be a fourth dimension and labor-intensive process for inexperienced DIYers.

DIY difficulty level: Intermediate

This repair requires mechanical knowledge and is not recommended for beginners.

Tools/parts needed (our top picks from Amazon):

FIXD
Mass Air Period Cleaner
Fuel Pressure Testing Gauge
Screwdriver
Pliers

STEP 1: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT.

Employ FIXD to scan your vehicle to verify the GM P0171 lawmaking is the only DTC present. If other codes are present, they must be addressed first.

STEP ii: INSPECT VACUUM LINES.

Audit all vacuum lines and hoses for leaks, and brand certain they are properly connected. If a leak is nowadays, y'all will hear a hissing sound, though it may be difficult to hear with the engine running. If you suspect a vacuum leak but are having trouble finding information technology, check out this detailed guide to finding vacuum leaks.

Step 3: INSPECT MASS AIR Menses (MAF) SENSOR.

Remove the mass airflow sensor and clean the sensor using mass air flow cleaner or contact cleaner.

> How to make clean your MAF sensor

Step 4: Audit EXHAUST Arrangement.

Check the exhaust organization components for leaks before the Air Fuel Ratio Sensors or Oxygen sensors; if yous find any leaks accept them repaired. Exhaust leaks can usually be spotted visually by a buildup of soot in the general vicinity of the leak.

STEP 5: CHECK FUEL Force per unit area.

Depression fuel force per unit area can throw off the air-fuel mixture ratio, and this could exist caused past anything from the fuel injectors and fuel pressure regulator to the fuel pump.

> How to check fuel pressure

Check fuel injectors: Brand sure the fuel injectors are functioning properly and activating. Random misfires tin can be a sign of faulty or clogged fuel injectors that need to be replaced. Also, check that the fuel injector wiring is not damaged and is connected properly.

> How to check fuel injectors past ear

> How to bank check fuel injectors with a digital multimeter

Pace 6: REPLACE AIR-FUEL AND/OR O2 SENSORS

At this point if the lawmaking still persists you may want to consider replacing your A/F sensor or O2 sensors.

Pace 7: Inspect AND REPLACE SPARK PLUGS

After you lot repair the cause of your P0171 code, inspect the spark plugs. If there is a white haze or crust on the tip of the spark plugs (nigh the diode that screws into the engine), then yous should replace all of the spark plugs .

Mutual P0171 diagnosis mistakes

Information technology is of import to consummate the entire diagnostic process when diagnosing P0171. Many people will replace the air-fuel sensor or O2 sensor every bit soon as they become a bad reading, but the root cause is often a dirty or faulty mass airflow sensor or vacuum leak, thus causing the O2 or A/F sensor to read differently to compensate. Reading and analyzing fuel trims and the freeze frame data is the cardinal to properly diagnosing P0171.

Even so Need Help Fixing Code P0171?

If you've followed the steps above and are yet experiencing a lean engine condition and GM P0171 code, please contact the FIXD Mechanic Hotline if you're a FIXD Premium subscriber or notice a RepairPal certified shop almost you to go the right repairs at a fair toll.