FTC Reader Disclosure: When you purchase or register through links on our site, we may earn an affiliate commission at no extra cost to you. Read our Editorial & Advertising Policy.

P0172 on Buick Envision: 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 Envision (2021–2026, 2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD)).

2021–2026
EnvisionSUV
Sensor Voltage Ref
0.1V – 5.0V Ref
Envision 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 Envision

When the Engine Control Module (ECM/PCM) on your Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD)) logs fault code P0172, drivers commonly observe:

Check Engine Light on on Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD))
Strong unburnt fuel odor from exhaust on Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD))
Black carbon soot around exhaust tip on Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD))
Rough idle and engine bogging under throttle on Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD))
Noticeable drop in MPG on Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD))
Buick Envision OBD-II Port Location
The 16-pin diagnostic connector is located Driver side lower dash trim. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Buick Envision

Historical warranty claims and technical repair bulletins for Buick Envision 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 Envision.

3. Step-by-Step DIY Repair Guide for Buick Envision

01
Clean MAF Sensor and Throttle Body

Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on the Buick Envision equipped with 2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD).

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 Envision equipped with 2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD).

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 Envision equipped with 2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD).

Other Common Fault Codes on Buick Envision

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

4. Buick Envision P0172 FAQs

What causes code P0172 to trigger on a Buick Envision?

On the Buick Envision (2.0L Turbo 4-Cyl (228HP / 258 lb-ft AWD)), 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 Envision?

On the Buick Envision, the 16-pin DLC diagnostic connector is located Driver side lower dash trim. 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 Envision 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.