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P2195 on Buick: Symptoms, Causes & Fix

O2 Sensor Signal Biased / Stuck Lean (Bank 1 Sensor 1)

Official technical diagnostic wire for fault code P2195 specifically affecting Buick vehicles (Enclave, Encore GX, Envision, Envista).

Sensor Voltage Ref
0.1V – 5.0V Ref
Buick Factory Standard
CAN Bus Speed
500 kbps CAN-FD
ISO 15765-4 Diagnostic Bus
Drivability Status
Drivable (Short Trip)
High urgency level
Est. Repair Cost
$150 - $450 (DIY: $60 - $180)
Parts & Labor DIY
Model-Specific Diagnostic Wires

Select Your Buick Model for P2195:

4 Models Available

1. Common Symptoms on Buick Vehicles

When Buick Engine Control Modules (ECM) trigger fault code P2195, drivers typically report:

Check Engine Light on on Buick Powertrains
Drop in fuel economy (15–20% MPG loss) on Buick Powertrains
Slight engine hesitation or black soot on exhaust tip on Buick Powertrains
Failed emissions test on Buick Powertrains

2. Root Causes on Buick Engines

Historical diagnostic claims across Buick engines point to the following failure distribution:

55%
Contaminated or failing upstream Air-Fuel Ratio (AFR) / O2 sensor (Buick OEM Part)
25%
Exhaust manifold crack or gasket leak before the sensor (Buick OEM Part)
12%
Severe intake air leak or unmetered air downstream of MAF (Buick OEM Part)
8%
Low fuel pressure or clogged fuel injector (Buick OEM Part)

3. Step-by-Step Fix Protocol for Buick

01
Inspect Bank 1 Exhaust Manifold for Cracks

Check exhaust manifold near Bank 1 Sensor 1 for cracks or blown gaskets sucking in fresh air. on Buick engines.

Required Tool: Flashlight, Mirror
02
Monitor Air-Fuel Sensor Current / Voltage

Check B1S1 AFR sensor output. On Toyota/Lexus, 3.3V is stoichiometric; a sensor stuck at 4.0V+ indicates lean bias. on Buick engines.

Required Tool: OBD-II Scanner
03
Introduce Propane/Carb Cleaner to Test Response

Briefly spray unlit propane into intake. If sensor voltage does not quickly drop rich, the sensor element is poisoned. on Buick engines.

Required Tool: Propane Torch Valve or Carb Cleaner
04
Replace Upstream Air-Fuel Ratio Sensor

Install a new genuine OEM Denso / Bosch upstream A/F sensor. on Buick engines.

Required Tool: 22mm O2 Sensor Socket, Ratchet
05
Clear Trouble Codes & Reset Fuel Trims

Clear DTCs, reset ECU learned trims, and road test. on Buick engines.

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Buick (P2195)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Buick OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Buick.

$45 – $95 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for BuickVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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4. Buick P2195 Frequently Asked Questions

What does code P2195 mean on a Buick?

On Buick vehicles, P2195 indicates that the Engine Control Module (ECM) detected o2 sensor signal biased / stuck lean (bank 1 sensor 1). This typically points to Contaminated or failing upstream Air-Fuel Ratio (AFR) / O2 sensor or Exhaust manifold crack or gasket leak before the sensor.

Can I continue driving my Buick with code P2195?

Caution. ECU may over-enrich fuel mixture trying to compensate for a falsely reported lean signal. Because this code carries a High severity rating on Buick powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code P2195 on a Buick?

Estimated DIY parts cost ranges from $150 - $450 (DIY: $60 - $180), while professional shop repairs at an authorized Buick dealership or independent specialist typically range from $180 to $380 including diagnostic labor.