P0144: O2 Sensor Circuit High Voltage (Bank 1, Sensor 3)

P0144 means the third oxygen sensor on Bank 1 (typically placed after a second catalyst stage or in commercial vehicle aftertreatment systems) is reporting a voltage that stays too high for too long, above roughly 1.0V. This code applies primarily to specific engine configurations with three sensors per bank, common on diesel commercial vehicles and some V6/V8 multi-converter setups.

P0144 is a emissions-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0144 and illuminates the check engine light.

If your vehicle has triggered P0144, you may notice one or more of these symptoms:

• Check engine light illuminated
• Increased fuel consumption in some cases
• Possible failed emissions test
• Usually no noticeable change in driveability
• May appear alongside P0420 or aftertreatment-system codes

Here are the most common causes of P0144, ranked by how likely they are to be the culprit:

Generally yes, for short-term driving. Safe to drive short term. Sensor 3 is a monitoring sensor in extended aftertreatment systems and does not drive fuel mixture, but persistent high voltage may signal a genuine rich condition or contamination that should be diagnosed within a few weeks.

Follow these steps to pinpoint the root cause of P0144:

1. Confirm the vehicle's exhaust layout. Sensor 3 is rare and only present on multi-catalyst configurations or diesel commercials with extended aftertreatment
2. Read freeze frame data and look for companion codes (P0172, P0175, P0420) that indicate a real rich condition or catalyst issue
3. Check long-term fuel trims. Significantly negative LTFT (under -10%) suggests a genuine rich condition rather than a faulty sensor
4. Inspect the Sensor 3 signal wire for shorts to voltage, especially near heat shields and chassis power runs
5. Substitute a known-good sensor. If high voltage persists, the issue is upstream (fuel mixture or wiring)

Repair costs for P0144 vary depending on the root cause and your vehicle. Here are typical estimates:

P0144 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:

These codes are often seen alongside P0144 or indicate related issues: