AutoCodeFix
🔍
EmissionsMinor✅ DIY Friendly

P0155

O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Heater element fault in upstream O2 sensor Bank 2.

SeverityMinor
CategoryEmissions
Est. Repair Cost$150–$400
Code TypePowertrain
DIY RepairYes

⚡ Common Causes

⚠️ Symptoms

✅ How to Fix — Step by Step

  • Step 1:Check fuse
  • Step 2:Test heater resistance
  • Step 3:Replace O2 sensor
  • Step 4:Check wiring
💡 Pro Tip: Heater circuit faults are more common in cold climates where sensors cycle more frequently.

Repair Cost Estimate

Full Repair Estimate
$150–$400
DIY Possible?
YES
Severity
Minor

Frequently Asked Questions

What does OBD2 code P0155 mean?+
P0155 stands for O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1. Heater element fault in upstream O2 sensor Bank 2.
What causes code P0155?+
Failed heater element; Wiring fault; Blown fuse
How do I fix code P0155?+
Check fuse; Test heater resistance; Replace O2 sensor; Check wiring
How much does it cost to fix P0155?+
Estimated repair cost for P0155 is $150–$400.
Is P0155 DIY-friendly?+
Yes — P0155 is generally DIY-friendly with basic tools.

AI Diagnosis

Related Codes

P0442Evaporative Emission Control System Small Leak Detected
MinorDIY
P0455Evaporative Emission Control System Large Leak Detected
MinorDIY
P0456Evaporative Emission Control System Very Small Leak
MinorDIY
P0135O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
MinorDIY
P0141O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 2
MinorDIY
P0136O2 Sensor Circuit Malfunction Bank 1 Sensor 2
MinorDIY