P2195: O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 1
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - fuel economy will suffer and the mixture may drift rich.
Symptoms
- Poor fuel economy
- Fuel smell from the exhaust
- Rough running in some conditions
Likely causes, most common first
- Upstream oxygen sensor stuck reporting lean
- Sensor contaminated by silicone or oil
- Exhaust leak ahead of the sensor
- Wiring or ground fault at the sensor
Read P2195 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P2195 means the bank 1 upstream sensor is biased lean - it still produces a signal, but the signal sits on the lean side and does not swing the way a healthy sensor does. The computer believes the engine is starving and adds fuel, so the real mixture ends up rich.
That inversion is what makes biased-sensor codes confusing: the code says lean while the tailpipe smells rich. Comparing the suspect sensor's live trace against the other bank's makes it obvious - one swings briskly across its range, the other loiters near the bottom.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P2195
“This is in reference to Field Service Action 13N02 with codes P2195 and P2197. There was an extended warranty, but I never knew that as I bought the vehicle pre-owned. I am a college student and the vehicle poses a danger as I am not able to stop every time. I called the local Ford dealership, and without even looking at the vehicle. He said, yes we know about the issue, but it's to late for you to have it repaired for free. I am filing a complaint with with the Wyoming Attorney General as well, and looking into a civil action. I want to make sure I document everything in case there is a serious injury or death.”2011 Ford Edge · Jul 2025
“The truck was running very rough. Found codes po171 and p2195 for o2 sensor stuck lean and bank 1 lean. Replaced b1s1 o2 sensor also mass air sensor. This truck has only 33,500 miles driven. Also had to reline front disc brakes ,replace front brake rotors and reline rear brakes and replace brake drums. This truck is not driven hard. Seems like alot of problems for only 33,500 miles. *utr”2007 Ford Ranger · Jun 2011 · 33,541 mi
Cars that report P2195 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P2195?
Yes - fuel economy will suffer and the mixture may drift rich.
How much does it cost to fix P2195?
Typical US repair costs range from $80 for the simplest fix (upstream oxygen sensor) to $600 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P2195. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.