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P0172 on Buick Encore GX: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0172 (System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix) specifically on the Buick Encore GX (2020–2026, 1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP)).

2020–2026
Encore GXSUV
Sensor Voltage Ref
0.1V – 5.0V Ref
Encore GX SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0172 On Another Buick Model:

1. Symptoms of P0172 on Buick Encore GX

When the Engine Control Module (ECM/PCM) on your Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP)) logs fault code P0172, drivers commonly observe:

Check Engine Light on on Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP))
Strong unburnt fuel odor from exhaust on Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP))
Black carbon soot around exhaust tip on Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP))
Rough idle and engine bogging under throttle on Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP))
Noticeable drop in MPG on Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP))
Buick Encore GX OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side lower dash near knee panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Buick Encore GX

Historical warranty claims and technical repair bulletins for Buick Encore GX point to the following failure distribution:

55%
Faulty or leaking fuel injector (Buick OEM Part)
25%
Contaminated Mass Air Flow (MAF) sensor (Buick OEM Part)
12%
Stuck closed EVAP canister purge valve (Buick OEM Part)
8%
Excessive fuel pressure regulator failure (Buick OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Buick Encore GX.

3. Step-by-Step DIY Repair Guide for Buick Encore GX

01
Clean MAF Sensor and Throttle Body

Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on the Buick Encore GX equipped with 1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP).

02
Check Short Term & Long Term Fuel Trims

Use live OBD-II scanner data; negative trims beyond -10% indicate the ECU is cutting fuel. on the Buick Encore GX equipped with 1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP).

03
Inspect Fuel Injector Leak-Down

Perform a fuel pressure leak-down test to identify injectors leaking raw gasoline into cylinders while parked. on the Buick Encore GX equipped with 1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP).

Other Common Fault Codes on Buick Encore GX

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Buick Encore GX:

4. Buick Encore GX P0172 FAQs

What causes code P0172 to trigger on a Buick Encore GX?

On the Buick Encore GX (1.2L Turbo 3-Cyl (137HP) / 1.3L Turbo 3-Cyl (155HP)), P0172 is most frequently caused by Faulty or leaking fuel injector or Contaminated Mass Air Flow (MAF) sensor.

Where is the OBD-II port located on my Buick Encore GX?

On the Buick Encore GX, the 16-pin DLC diagnostic connector is located Under driver side lower dash near knee panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Buick Encore GX with code P0172?

Driveable short distances, but unburnt fuel can damage catalytic converters. Given that P0172 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.