Fix P013A: Mechanic’s solutions that WORKED

The code P013A: O2 Sensor Slow Response – Rich to Lean (Bank 1 Sensor 2) points out a fault in the oxygen sensor’s ability to switch between rich and lean conditions in a timely manner, and it’s most likely caused by exhaust leaks or faulty O2 sensors.

P013A quick overview

Meaning	P013A: O2 Sensor Slow Response – Rich to Lean (Bank 1 Sensor 2)
Is it serious?	Yes, it can affect fuel efficiency, emissions, and overall engine performance.
Possible causes	– Exhaust leaks, especially near the O2 sensor – Faulty or inefficient O2 sensors, especially if aftermarket – Lean condition in the fuel mixture – Potential issues with the vehicle’s powertrain control module (PCM) or software – Internal issues in the catalytic converter
How to diagnose?	Inspect for Exhaust Leaks: Check the exhaust system, especially around the O2 sensor, manifold, or downpipe connection. Look for any pinhole leaks or porous welds. Examine O2 Sensors: Ensure they are original equipment (OE) parts. Aftermarket sensors might not be as efficient or compatible. Monitor O2 Sensor Performance: Use diagnostic tools to observe how the O2 sensors transition between rich and lean conditions. Check for PCM or Software Updates: Visit the dealership or use diagnostic tools to see if there are any updates or technical service bulletins (TSBs) related to the vehicle’s PCM or software. Evaluate Fuel and Injector Conditions: A lean condition can affect O2 sensor performance. Consider using top-tier fuel with injector cleaner or checking the injectors for potential issues.

How to fix P013A – learn from mechanics

I looked into P013A 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: Kia

Vehicle Information 2002 Kia Sportage 2.0L

Issue + Repair History MIL lamp on leading to inspection failure. Code on inspection paperwork indicated an issue, but two scanners reported it as an INVALID code. After code clearing, an OBD2 drive cycle was performed, but CAT monitor and EVAP monitor did not set. No pending codes or Mode5 failures were observed. It was suspected that these might set after refueling the vehicle.

Other OBD2 Codes + Test Results
P013A

What Are People Suggesting to Fix Issue A technician mentioned that p013a is a hex code for the linear O2 sensor bank1 sensor2.

What Was the Final Fix There was a glitch in the Sportage OBD2 software, first identified in 2002. The P013A was mentioned in a technical bulletin from 2002 and describes this issue. This code is meant to follow a diagnostic routine for a code P0140. The solution was to replace the rear O2 sensor. After this, both the EVAP and the Catalyst readiness monitors tested successfully on the next drive cycle, allowing the vehicle to pass inspection without any issues.

Case #2: GMC

Vehicle Information 2012 GMC Yukon XL 1500 Denali 6.2L

Issue + Repair History Six months prior, the vehicle had codes p0138 and p013E for B1S2. After 6000 miles and replacing B1S2, it displayed P013A and P2271 for the same sensor. There wasn’t a significant difference observed between the post-catalytic sensors. A difference was noted between the pre-catalytic sensors, which seemed to stay rich for a prolonged period at idle, briefly going lean, then returning to rich. During acceleration, they were relatively active. The vehicle is flex-fuel with a 15% alcohol content, which was verified through testing.

Other OBD2 Codes + Test Results
P013a – Slow response rich to lean B1S2
P2271- Signal stuck rich B1S2

What Are People Suggesting to Fix Issue

• One technician emphasized the importance of replacing all sensors simultaneously, noting that O2 sensors tend to slow down over time, which can confuse the PCM.
• Another mentioned a TSB suggesting the use of a smoke machine to detect any vacuum, exhaust, or intake leaks.
• A technician inquired about any broken exhaust manifold bolts.
• Another found it intriguing that P013A must run and pass before P2271 can fail. He suggested checking if the front sensors hang high before the catalytic converters light up, which would cause the rear sensors to also hang high. He also inquired about any suspiciously high/low trims and the duration for which the pre-catalytic O2 sensors hang high.

What Was the Final Fix Both front O2 sensors were replaced, and B1S2 was replaced again as a precautionary measure. The front sensors were suspected to be occasionally lazy but not enough to set codes, while the rear accurately reflected the actual conditions, leading to the code being set.

Case #3: Dodge

Vehicle Information 2010 Dodge Journey SXT 3.5L

Issue + Repair History The vehicle displayed a P013A trouble code after moving to CO and having a water pump replaced in CA. Since then, the 1/2 O2 sensor and PCM were replaced, O2 sensor signal circuits were tested multiple times, exhaust leaks were checked, the timing cover was inspected for rear bank cam index, and other unrelated parts like the clockspring and radio were replaced. Despite these efforts, the code would reappear days or weeks later after being cleared. Both the previous and current owners reported occasional poor engine performance, but this was not confirmed during test drives. The code is set under specific conditions, including speeds over 60 mph, sustained open throttle operation for over 2 minutes, normal operating temperature of the catalytic converter and engine, and when the downstream O2 sensors are in a rich/high voltage mode.

Other OBD2 Codes + Test Results P013a- O2 sensor 1/2 slow response rich to lean

What Are People Suggesting to Fix Issue

• Consider doing a decarbon job on the vehicle.
• Check for exhaust leaks.
• Verify circuit integrity for the O2 in question and inspect for any improperly routed harness or connection issues.
• Ensure the correct O2 sensor was replaced and consider checking for PCM software updates at a dealer.
• Replace both O2 sensors on the bank in question and disconnect the battery after any O2 replacement to force the PCM to relearn the heater resistance.
• Use 10-12 psi regulated air for smoke tests to detect tiny leaks.
• Consider replacing the catalytic converter.
• Use a factory O2 sensor for replacement.
• Always replace the upstream oxygen sensor when replacing the downstream sensors.

What Was the Final Fix A rear bank catalytic converter (maniverter) was replaced, which seemed to resolve the issue. The assumption was that the catalytic converter had internal flow issues that slowed the 1/2 O2 sensor’s switch-to-lean response.

Case #4: Jeep

Vehicle Information 2007 Jeep Commander 4.7L

Issue + Repair History The vehicle displayed a P013A trouble code. The O2 sensor and PCM were tested, and the O2 sensor was replaced. Despite these efforts, the code reappeared after a test drive. The vehicle is not a flex fuel vehicle. The code is set under specific conditions, and the vehicle’s catalytic converter efficiency is closely controlled.

Other OBD2 Codes + Test Results P013a- O2b1s2 rich to lean switch time too long

What Are People Suggesting to Fix Issue

• Perform an exhaust system integrity check for leaks.
• Check for any Technical Service Bulletins (TSBs) or updates.
• Pressurize the tailpipe to a regulated 12-15 psi and use soapy water to check for leaks, especially around the O2 sensor and welds.
• Ensure the PCM is at the latest flash level as there were updates to open up the tolerance for setting this code.
• Consider using JB weld for a fix if a leak is found, instead of replacing expensive parts.
• Use “Mr. Bubbles” kiddie bubble solution or commercially available ‘gas leak detector’ to detect tiny leaks.

What Was the Final Fix There was a flash for the problem, and the vehicle was sent to the dealer. An exhaust system integrity check was performed, and no leaks were found. The assumption was that the vehicle’s software was sensitive, and the flash update resolved the issue.

Case #5: Chevrolet

Vehicle Information 2013 Chevrolet Suburban 1500 LT 5.3L

Issue + Repair History The vehicle displayed a P015d code. The O2 sensors were replaced, which resolved the P013a code that was also present, but the P015d code persisted. There was difficulty in finding a diagnostic flowchart for this specific code. The vehicle was fitted with aftermarket parts.

Other OBD2 Codes + Test Results P015d- Bank 2 sensor 1 delayed response

What Are People Suggesting to Fix Issue

• Conduct a standard exhaust back pressure (BP) test on both sides.
• Check for any pinhole exhaust leaks prior to the O2 sensor, especially at the manifold or downpipe connection.
• Use a smoker to pressurize the exhaust and apply soap bubbles to detect any leaks.
• Investigate a potential lean condition on bank 2 and see if it can be forced rich. If it reacts quickly when forced rich, then determine the cause of the lean condition.
• Consider the possibility of an issue with the voltage feed supply to the O2 heaters, which could affect their operation.
• Run a couple of tanks of top-tier fuel with injector cleaner to see if that resolves the DTC.

What Was the Final Fix Replacing the aftermarket parts with original equipment (OE) parts resolved the problem. It was noted that there was a significant difference between the like-branded parts, even if they seemed to be made by the same manufacturer.

Advice	Brief Description of Diagnostic Step
Check for Exhaust Leaks	Inspect the exhaust system for any pinhole leaks, especially around the O2 sensor, manifold, or downpipe connection. Use methods like pressurizing the exhaust with a smoker or regulated shop air and applying soap bubbles to detect leaks.
Replace O2 Sensors with OE Parts	If aftermarket O2 sensors were used, consider replacing them with original equipment (OE) parts. Aftermarket parts might not always be compatible or as efficient.
Monitor O2 Sensor Performance	Observe how the O2 sensors transition between rich and lean conditions. A slow transition might indicate a problem.
Consider PCM or Software Updates	Check if there are any updates or technical service bulletins (TSBs) related to the vehicle’s powertrain control module (PCM) or software that might address the issue.
Check Fuel and Injector Conditions	A lean condition in the fuel mixture can affect O2 sensor performance. Consider running top-tier fuel with injector cleaner to address potential injector issues.