P013A Code: O2 Sensor Slow Response – Rich to Lean (Bank 1 Sensor 2)

Oxygen sensors play a vital role in the operation of your engine. They are installed either in the exhaust manifold or in the exhaust pipe (downstream from the manifold). The main function of these sensors is to measure the amount of oxygen in the exhaust. This information is used by the vehicle’s powertrain control module (PCM) to adjust air-to-fuel ratio accordingly.

Just like any other engine sensor, these sensors can develop problems because of several reasons. P013A is just one of several engine trouble codes related to a possible fault with the performance of one of the vehicle’s oxygen sensors. If your scan tool reads this code, and you’re wondering what it means, you’re reading the right article.

What Does the P013A Code Mean?

Diagnostic trouble code (DTC) P013A stands for “O2 Sensor Slow Response – Rich to Lean (Bank 1 Sensor 2).” It is logged once the PCM perceives that the post-catalytic converter oxygen sensor (Sensor 2) in Bank 1 is responding slowly. Bank 1 refers to the side of the engine that contains cylinder #1.

Code P013A indicates a problem with the downstream O2 sensor, which is already supposed to be lazier than the upstream sensor on a system where the catalyst is storing oxygen correctly.

Conventional oxygen sensors actually use their ceramic electrolyte-based zirconia bulb to compare oxygen in the exhaust stream to atmospheric oxygen – and at 600 degrees F they  create their own voltage (0.2 to 0.9 volts), which the PCM uses to determine O2 content in the exhaust stream. The downstream sensor works like the upstreams sensor but has a slightly different job; it measures the catalytic converter’s oxygen storage capacity.

Code P013A indicates a problem with the downstream O2 sensor, which is already supposed to be lazier than the upstream sensor on a system where the catalyst is storing oxygen correctly.

– Richard McCuistian, ASE Certified Master Automobile Technician

Generally, if the amount of oxygen in the exhaust is high (lean condition), the voltage signal should be low. On the other hand, low oxygen concentration in the exhaust (rich condition) should trigger a higher voltage signal.

The PCM uses the data from the upstream oxygen sensor when calculating how much fuel to give the engine. Meanwhile, the PCM primarily uses the signal from the downstream sensor to determine the health of the catalytic converter.

Once the PCM detects a slow response time from the oxygen sensor (Bank 1 Sensor 2) over a set period, it will trigger code P013A.

Note: The definition of code P013A may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P013A Code?

Here are some possible triggers of the P013A engine code:

• Faulty oxygen sensor (bank 1, sensor 2)
• Wiring and/or connector issues
• Malfunctioning catalytic converter
• Leaks in the engine exhaust
• An issue with the PCM
• Engine running too rich or too lean

What are the Common Symptoms of a P013A Code?

Here are some common symptoms of this error code:

• Illuminated check engine light
• Decreased fuel efficiency
• Poor engine performance

How to Diagnose the P013A Code

You can try diagnosing code P013A using a scan tool record utility. The ECM/PCM knows how rapidly the downstream (rear) O2 sensor should be switching based on the faster switching upstream sensor. It’s a rationality check algorithm. Usually the downstream (1/2 and 2/2) sensors will be more sluggish anyway by default, but the ECM/PCM knows when there’s something wrong, and it’ll flag a sluggish downstream sensor when it detects that. Usually the upstream sensor dies first, though, and that’s a different code.

Note, however, that it isn’t easy to diagnose P013A. Considering that there are several faulty components that may trigger the code, it may be difficult for you to identify which one is causing the issue. If you’re not well-versed in auto repair, it’s best to take your vehicle to an auto repair shop and let a mechanic inspect your vehicle.

If you’re confident about diagnosing the code yourself, it’s a good idea to start by reading  vehicle-specific repair manuals or online repair databases. They can help you identify the diagnostic procedures that may be compatible with your vehicle.

How to Fix the P013A Code 5

It isn’t easy to fix issues with any vehicle sensors, especially if you don’t have adequate knowledge and the appropriate tools to get the job done. You can always choose to bring your vehicle to an auto repair shop and let a mechanic fix the issue for you.

However, if you don’t mind spending the money and you’re wrench smart, throw a sensor at it yourself – that’s pretty likely to be the problem in a situation like this. We also suggest consulting vehicle-specific repair manuals or subscribing to an online repair database to help you determine the appropriate fix.

When consulting these resources, it’s important to remember that vehicles may be structured differently per manufacturer. For instance, the repair steps for a P013A on a Ford may be different for a P013A on a Chevrolet.

Get a High-Quality, Affordable Oxygen Sensor

One of the possible reasons for the P013A code is the bad oxygen sensor in the bank 1 sensor #2 position. Avoid more issues with the engine by replacing the faulty sensor at the earliest possible date. Fortunately, a reliable oxygen sensor for your car is only several clicks away here at CarParts.com.

CarParts.com is your one-stop shop for oxygen sensors and other world-class parts at competitive prices. We exclusively source our products from brands trusted by drivers across the US, so you can be sure to get a part that delivers long-lasting performance. Find the component that fits your specific application and budget by entering your vehicle’s details into our website’s built-in vehicle selector. If you live in the continental US and place your order before noon ET, you can expect to receive your new oxygen sensor in as fast as two business days.

Get big savings on reliable replacement oxygen sensors here at CarParts.com. Take a look at our extensive selection of oxygen sensors and get a great deal today!