Fix P013E: Mechanic’s solutions that WORKED

The code P013E: “O2 Sensor Delayed Response – Rich to Lean (Bank 1 Sensor 2)” indicates that the downstream oxygen sensor on Bank 1 is not switching from rich to lean as quickly as it should. This sensor monitors the efficiency of the catalytic converter and helps manage fuel economy and emissions.

The downstream oxygen sensor (after the catalytic converter) on Bank 1 is responding more slowly than expected when the fuel mixture changes from rich (too much fuel) to lean (not enough fuel).

P013E quick overview

Meaning	P013E: “O2 Sensor Delayed Response – Rich to Lean (Bank 1 Sensor 2)”
Is it serious?	Yes, it can be. If not addressed, it may lead to reduced fuel efficiency, increased emissions, and potential damage to the catalytic converter.
Possible causes	– Faulty or aging downstream oxygen sensor (Bank 1 Sensor 2) – Exhaust leaks affecting the sensor readings – Contaminated or malfunctioning fuel injectors – Issues with the catalytic converter – Wiring or electrical problems affecting the oxygen sensor circuit
How to diagnose?	Check for Technical Service Bulletins (TSBs): Manufacturers might have released updates or notices regarding common issues related to this code. Inspect and Test the Oxygen Sensor: Ensure that the downstream oxygen sensor on Bank 1 is functioning correctly and is not contaminated or aged. Check for Exhaust Leaks: Small leaks, especially near the oxygen sensor, can affect readings and should be addressed. Evaluate Fuel Injectors: Dirty or malfunctioning fuel injectors can cause a rich condition that the sensor might be detecting. Examine Catalytic Converter: A failing catalytic converter can cause changes in exhaust composition, affecting sensor readings. Inspect Wiring and Connectors: Look for damaged wiring or poor connections that might be affecting the oxygen sensor’s signal.

How to fix P013E – learn from mechanics

I looked into P013E 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 knock sensor issue. They also always report the fix that worked for the vehicle so this section will be like having a real mechanic helping you solve your issue.

Almost all of these were left without confirming the fix by a technician, however, the community suggestion to diagnose this code will help you get an idea of what to do.

Case #1: GMC

Vehicle Information 2012 GMC Yukon XL 1500 Denali 6.2L, MIL Lamp on

Issue + Repair History

• Six months ago, had codes P0138 and P013E for B1S2.
• 6000 miles later, after replacing B1S2, it set P013A and P2271 for the same sensor.
• Both precat sensors stay rich at idle, sweep lean briefly, then return to rich.
• During acceleration, sensors are relatively active.
• Vehicle is flex fuel with 15% alcohol content, confirmed by testing.
• Other mentioned fault codes: P0138, P013E

Other OBD2 Codes + Test Results

• No additional codes or test results mentioned.

What Are People Suggesting to Fix Issue

• Replace all O2 sensors at the same time, as they tend to slow down over time.
• Use a smoke machine to check for vacuum, exhaust, or intake leaks.
• Check for any broken exhaust manifold bolts.
• Investigate if the precat O2 sensors hanging high is due to a degraded front O2 sensor.

What Was the Final Fix

• Replaced both front O2 sensors and replaced B1S2 again as a precaution.
• The vehicle has been running without issues since the repair.

Case #2: Chevrolet

Vehicle Information
2010 Chevrolet Suburban 1500 LTZ 5.3L, Excessive Emissions, No Start

Issue + Repair History

• Came in with a no start problem and 12 codes: P0219B, P0521, P0573, P1380, P0053, P0054, P0060, P0172, P0175, P0300, P013E.
• Truck was flooding the cylinders with fuel.
• Temp sensor reading was 60.8 degrees in a 65-degree shop.
• Engine oil pressure fluctuated between 2.32 to 11 when trying to start.
• Barometric pressure read 14.79 psi.
• Fuel Alcohol Content was initially 76.8%, reset to 3.14%.
• Resetting stopped the truck from dumping fuel into the cylinders.
• Fuel trim reading was 14, MAF was 2.31 when spinning over, MAP read 14.64 psi.
• Disconnected exhaust from the cats, noticed flames blowing out but still no start.
• Changed spark plugs and the MAP sensor.
• Checked timing and it was good.
• Backfires through the throttle body, suggesting a timing problem.
• Compression to be checked.

Other OBD2 Codes + Test Results

• P0521: Engine oil pressure sensor performance.
• P219B: Fuel trim cylinder balance bank 2.
• P0053: H02S heater resistance bank 1 sensor 1.
• P0172: Fuel trim system rich bank 1.
• P0175: Fuel trim system rich bank 2.
• P013E: H02S delayed response rich lean bank 1 sensor 2.

What Are People Suggesting to Fix Issue

• Check if valves are sticking open and ensure good compression.
• Possible ground problem, clear codes and retest.
• Check compression and scope crank and cam sensors.
• Test drive to see which codes return as “CURRENT”.
• Confirm if oxygen sensors are accurate and test for fuel contamination.
• Clear all codes and see which ones return, then address one at a time.
• Check for damage on the wiring harness and clean/tighten grounds.
• Check for a ground/power issue with the harness causing codes and backfiring.
• Check voltage at the ECT and AIT, and also the MAF sensor.
• Check fuel quality and alcohol content, especially if the vehicle is flex-fuel.
• Check if it’s an AFM issue holding valves closed or open.
• Use a gas analyzer to sniff inside the coolant system for hydrocarbon readings.

What Was the Final Fix

• The final fix was not confirmed by technician

Case #3: Chevrolet

Vehicle Information
2009 Chevrolet Traverse LTZ 3.6L, Poor Fuel Economy, MIL Lamp on

Issue + Repair History

• Originally set DTC P2099 and found one of the post-cat O2 sensor’s heater shorted.
• Replaced all four O2 sensors due to vehicle age and to avoid future issues.
• MIL stayed off for several weeks, then intermittently came on.
• No exhaust leaks found after smoking the system.
• Fuel trims are reading great, no vacuum leaks found.
• TSB concerning exhaust leaks checked but no leaks found.
• Re-welded a joint at the catalytic converter due to moisture seepage.
• Further investigation into the fuel system and MAF planned.

Other OBD2 Codes + Test Results

• P2099: Lean

What Are People Suggesting to Fix Issue

• Check if the new O2 sensors are causing the issue, possibly replace them again.
• Use soap bubbles with regulated low shop air to detect exhaust leaks.
• Pressurize the exhaust with shop air and use soap and water to check for leaks.
• Check the front O2 against the rear at steady light load conditions.
• Check the quality of the replacement O2 sensors, OE or aftermarket.
• Run cleaner through the injectors and switch to a top-tier fuel with higher detergent levels.
• Check for vacuum leaks, exhaust tightness, MAF cleanliness, injector functionality, and ethanol content in fuel.
• Consider the possibility of a defective cat, O2 sensor, or PCM damage from the shorted heater.
• Perform a fuel injector balance test and injector solenoid coil test.

What Was the Final Fix

• The final fix was not provided as the shop vehicle had to wait its turn for further investigation and repair.

Case #4: Cadillac

Vehicle Information
2008 Cadillac CTS 3.6L, MIL Lamp on

Issue

• Intermittently sets the code P2097 (Post Catalyst Fuel Trim System High Limit Bank 1).
• Code sets very intermittently, sometimes taking a week or 400-500 miles at over 70 mph to return.
• Fuel trims look fine, and no other codes are set.

Diagnostic Steps Taken

• Checked all wiring and heater as code is for O2S downstream voltage high.
• Replaced O2 sensors with OEM parts, but the code still sets.
• Freeze frame shows that the codes set at above 70 MPH but fuel trim looks fine.
• No software update found for this code.

Suggestions from Other Technicians

• Check for exhaust leaks, possibly very small and hard to locate. An ultrasonic leak detector may assist in finding the leak. Check the seal between the exhaust pipe and converter, and the welds around the HO2 sensor fitting for pinholes.
• If there are pinholes in the welds around the sensor on the converter, the vehicle may qualify for free replacement at a dealership under federal emissions coverage (8 yrs/80,000 miles warranty on the catalytic converter).
• Follow the GM techline diagnostic steps for DTC P2097 or P2099.
• Check if the DTC isn’t for a vehicle overspeed condition.
• Consider using a Crecorder from Launch to get a freeze frame when the code sets and the data stream the whole time it’s on the car.
• Check the injectors, possibly in need of cleaning. Use GM top engine cleaner and fuel additive to flush the injectors.

Final Fix

• The final fix was not provided as the technician was still trying to pinpoint the problem. Further diagnostic steps and possibly following the suggestions from other technicians would be necessary.

Advice	Brief Description of Diagnostic Step
Check for Exhaust Leaks	Inspect the exhaust system for any leaks, especially around the O2 sensor and catalytic converter, as they can affect sensor readings.
Inspect O2 Sensor and Wiring	Examine the downstream O2 sensor for any signs of damage or contamination. Also, check the wiring and connectors for corrosion or damage.
Look for TSBs or Software Updates	Check for any Technical Service Bulletins or software updates from the manufacturer that might address this specific issue.
Test O2 Sensor Response	Use a scan tool to monitor the O2 sensor’s response time from rich to lean to verify if it’s within the manufacturer’s specifications.
Consider Catalytic Converter Health	Evaluate the condition of the catalytic converter, as a failing converter can affect the O2 sensor’s readings.