Fix P013B: Mechanic’s solutions that WORKED

The code P013B: O2 Sensor Slow Response – Lean to Rich (Bank 1 Sensor 2) points out a delayed response in the transition from lean to rich of the O2 Sensor located in Bank 1 Sensor 2. This is most likely caused by a faulty O2 sensor, exhaust leaks near the sensor, or issues related to the engine’s air-fuel mixture.

P013B quick overview

Meaning	P013B: O2 Sensor Slow Response – Lean to Rich (Bank 1 Sensor 2)
Is it serious?	Yes. While the vehicle might still run, it can lead to reduced fuel efficiency, increased emissions, and potential damage to the catalytic converter over time.
Possible causes	– Faulty or aging O2 sensor (Bank 1 Sensor 2). – Exhaust leaks near the O2 sensor. – Contaminated or damaged O2 sensor. – Faulty fuel injector or fuel pressure issues. – Engine vacuum leaks. – Issues with the engine’s air-fuel mixture.
How to diagnose?	Visual Inspection: Check the O2 sensor wiring and connections for signs of damage or wear. Scan Tool Data: Use a scan tool to observe live O2 sensor data. Compare the performance of Bank 1 Sensor 2 to other O2 sensors. Check for Exhaust Leaks: Inspect the exhaust system for leaks, especially near the O2 sensor. Test the O2 Sensor: Using a multimeter or scan tool, check the O2 sensor’s voltage response to changes in the air-fuel mixture. Inspect Fuel System: Ensure that fuel injectors are functioning properly and that there’s appropriate fuel pressure. Check for Vacuum Leaks: Inspect the engine for vacuum leaks which can affect the air-fuel mixture.

How to fix P013B – learn from mechanics

I looked into P013B service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Volkswagen

Vehicle Information 2010 Volkswagen Jetta TDI 2.0L

Issue + Repair History

• MIL lamp on
• Codes: 12812, 1162, p320c
• Erased the same codes in January.

Other OBD2 Codes + Test Results

• 12812: No description available
• 1162: No description available
• p320c: No description available

What are people suggesting to fix the issue

• DTC Description P013B (00315) suggests O2 Sensor Bank 1 Sensor 2 Slow Response Lean to Rich.
• DTC Description P320C (12812) suggests O2 Bank 1 Sensor 1/2 Lean Correlation.
• Improved ECM software calibration to stabilize O2 Sensor diagnosis.
• O2 Sensor diagnosis might be too sensitive causing MIL ON.
• Optimize EGR filter assembly process and introduce new ECM software.
• Loosen EGR filter assembly in exhaust system to neutralize its position.
• Software update for the issue.

What was the final fix The issue was related to the O2 sensor in front of the catalyst.

Case #2: Chevrolet

Vehicle Information 2008 Chevrolet Colorado LT 3.7L

Issue + Repair History

• Trouble getting O2 or Evap monitor to run for IEPA emissions test.
• Evap monitor runs the first part consistently and also runs the key off portion.
• Engine running portion pulls -10.4″ H2O of vacuum in the tank.
• Evap Service Bay Test starts but doesn’t end during the engine running portion.
• Ambient temp PID drops to 32F on the road.
• O2 monitor doesn’t run despite several attempts and strategies.
• Replaced B1S1 O2 Sensor & B1S2 O2 Sensor and Evap vent control solenoid.
• Had 1 cam timing code P0014, did not return.
• Also had P0300, did not return.
• Codes not passed since code clear: P2270, P2271, P013A, P013B, P0442, P0451, P0454, P0464.

Other OBD2 Codes + Test Results

• P0449: Evap Vent Solenoid Circuit
• P013a: B1S2 O2 Sensor Slow response rich to lean
• P2270: B1S2 O2 Sensor signal stuck lean
• P2271: B1S2 O2 Sensor signal stuck rich
• P0140: B1S2 O2 Sensor insufficient activity
• P2271: B1S1 O2 Sensor Rich/Lean switch signal malfunction (OBD2 side)

What are people suggesting to fix the issue

• Check cat operation with a functioning rear O2 sensor.
• Look at MODE6 data for potential issues.
• Ensure engine temp reaches operating temp quickly.
• Ensure fuel level is above 1/4 for Evap to run.
• Consider throttle body service.
• Use Tech 2 or Snap-on tool to force the Evap monitor.
• Check for “pending” codes and consider a PCM reflash.
• Trick the Ambient Temp Sensor PID to read warmer.
• Ensure engine temp reaches 195F for the oxygen sensor monitor to run.
• Consider the possibility of a bad thermostat.
• Check if the vehicle requires the addition of at least 4 gallons of gas to pass EVAP.
• Ensure the right O2 sensor is being used.

What was the final fix The vehicle passed with the O2 monitor running, making 4 out of 5 non-continuous monitors ready. Decelerations seemed to be the key for the O2 monitor to run. The technician suggests using the vehicle for errands or returning it to the customer for a week and then checking readiness. The ambient temp sensor in the rear view mirror was clarified to be for HVAC purposes, and the engine management Ambient temp is inferred from IAT. GM has become problematic in readiness monitors, with O2 monitor and EVAP EONV being issues. GM has received exemptions on readiness from the EPA.

Advice	Brief Description of Diagnostic Step
Check O2 Sensors	Ensure the O2 sensors are functioning correctly. Consider replacing if old or malfunctioning.
Monitor Ambient Temperature	Ambient temperature can influence the running of certain monitors. Ensure it’s within the required range.
Use Mode 6 Data	Mode 6 data can provide insights into specific issues and parameters that might not be meeting the criteria.
Ensure Engine Temperature	Make sure the engine reaches the operating temperature quickly. A malfunctioning thermostat might prevent certain monitors from running.
Check Fuel Level	For Evap monitors to run, the fuel level should be within a specific range, typically above 1/4.
Deceleration Strategy	For O2 monitors, repeated decelerations might be key to getting the monitor to run.
Check for Pending Codes	Pending codes can prevent certain monitors from setting. Ensure there are no pending codes in the system.
Use Diagnostic Tools	Tools like Tech 2 or Snap-on can be used to force certain monitors to run, especially the Evap monitor.
Ensure Correct Parts	Make sure the correct and compatible parts (like O2 sensors) are being used for the specific vehicle model.