What Does P2195 Mean?
The upstream oxygen sensor on Bank 1 is stuck reading a lean condition and not switching properly between rich and lean signals. The PCM expects to see voltage oscillation between approximately 0.1-0.9V, but the sensor remains biased lean (low voltage).
Common Causes
45%
Failed or contaminated oxygen sensor unable to respond to mixture changes
25%
Exhaust leak before the oxygen sensor allowing fresh air to contaminate readings
15%
Damaged or corroded oxygen sensor wiring or connector
10%
Actual persistent lean condition on Bank 1 causing constant lean reading
5%
PCM internal fault or software issue affecting sensor processing
Diagnostic Steps
1
Step 1: Monitor live O2 sensor voltage on Bank 1 Sensor 1 and verify it's stuck low (below 0.3V typically)
2
Step 2: Perform propane enrichment test near intake to see if sensor responds to artificially rich condition
3
Step 3: Inspect exhaust manifold and connections before O2 sensor for leaks using visual and audible inspection
4
Step 4: Check O2 sensor wiring and connector for damage, corrosion, or water intrusion
5
Step 5: Review fuel trim data on Bank 1 to determine if actual lean condition exists or if sensor is faulty
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
The upstream oxygen sensor on Bank 1 is stuck reading a lean condition and not switching properly between rich and lean signals. The PCM expects to see voltage oscillation between approximately 0.1-0.9V, but the sensor remains biased lean (low voltage).
The most common cause of P2195 (O2 Sensor Signal Stuck Lean Bank 1 Sensor 1) is: Failed or contaminated oxygen sensor unable to respond to mixture changes
Typical repair costs for P2195 range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but will fail emissions testing and may experience poor fuel economy. PCM cannot properly adjust fuel mixture leading to potential engine performance issues.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2195 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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