Replacing Oxygen Sensors Can Prevent Costly Repairs

Replacing Oxygen Sensors Can Prevent Costly Repairs

Sponsored by NTK Oxygen Sensors

Did you know replacing worn or failed oxygen sensors is the best way to protect expensive three-way catalysts or catalytic converters? Failure to replace failed oxygen sensors at the earliest sign of a problem, usually indicated by an illuminated check engine light, can cause premature failure of expensive three-way catalysts or catalytic converters.

What does it mean to have a failed oxygen sensor? When an oxygen sensor fails, it is no longer communicating with the vehicle’s Engine Control Unit. The ECU is responsible for strengthening or weakening the fuel delivery through the fuel injectors in order to maintain the most desirable air fuel ratio, usually close to 14.7 part air to 1 part fuel (14.7:1), also known as the stoichiometric point. When the oxygen sensors and the ECU are not communicating, the vehicle is programmed to revert to what is known as open-loop mode, in which more fuel is delivered to protect the engine from damage from an over lean condition. Running in open loop mode will not only waste fuel, and increase emissions, but will also put undue stress on the three-way catalyst.

The role of the three-way catalyst is to convert harmful gasses: carbon monoxide, nitric oxide and nitrogen dioxide (both referred to as NOx), and hydrocarbons to less harmful gases, such as carbon dioxide, nitrogen, oxygen, and water vapor. To do this, expensive precious metals such as platinum, rhodium, and palladium are used to create chemical reactions. Unused fuel (hydrocarbons) is removed by burning inside the oxidation catalyst.

When the vehicle is operating in open loop mode, the engine will run rich, resulting in much higher levels of unburned fuel. Vastly elevated temperatures inside the oxidation catalyst in the three-way catalyst will eventually lead to a melt down and a destroyed catalytic converter. Often, once the catalyst has been destroyed, vehicle performance will also suffer, sometimes resulting in an engine that will no longer run because of a plugged exhaust.

Ignoring that check engine light is the worst thing you can do for your three-way catalyst(s). Replacing a failed oxygen sensor at the earliest sign of trouble may save future headaches and higher repair bills.

If you have questions about oxygen sensor replacement or increasing engine performance, you can reach out to NTK Oxygen Sensors by calling their Technical Services line at 877-4-SENSOR or visit them on the web at

You May Also Like

A Closer Look: Standard® Gasoline Direct Injection (GDI)

Gasoline direct injection (GDI) is used on most new vehicles and requires a different approach to diagnosis and service. GDI technology has been an integral part of helping to improve fuel economy while reducing emissions, and can be found on more than half of the U.S. fleet. In fact, the use of GDI engines has

Gasoline direct injection (GDI) is used on most new vehicles and requires a different approach to diagnosis and service. GDI technology has been an integral part of helping to improve fuel economy while reducing emissions, and can be found on more than half of the U.S. fleet. In fact, the use of GDI engines has grown by over 600% since 2010. While GDI systems have been largely useful, these systems encounter specific failures and require an understanding of how they work and how to test them when they set a code.

Overcoming Supply Chain Issues in Today’s World

Many legislative and environmental mandates have affected the collision repair industry over the last decade. To comply with such mandates, vehicle manufacturers continue to design vehicles with increasingly advanced electronics, ranging from Advanced Driver Assistance Systems that increase safety, helping people with everything from parking to driving, to the recent push for electric vehicles. They’ve

Two Lubegards Are Better Than One

Lubegard Synthetic ATF Protectant and Instant Shudder Fixx work better, faster and longer together to stop torque-converter clutch shudder (TCC shudder). Both products are effective on their own, but when used together they not only provide a long-term solution for TCC shudder but also offer complete protection for transmissions. Since the 1980s, lockup torque convertors

High Oil Consumption?

A common question an OEM oil supplier like ENEOS sees is how to tell when oil consumption becomes excessive? Since a few factors could be involved, here are some of the potential implications. How much is too much?First, because of wear, vehicles are more likely to consume engine oil as they age. Common culprits that

The Value of Replacing the Water Pump and Timing Belt Simultaneously

Water pumps have long been considered the heart of a vehicle’s cooling system. Although its sole function – pumping coolant from the radiator through the engine – seems simple, it’s a crucial process to keep engines running at optimal temperatures. Unfortunately, some drivers can overlook this – along with proper care for the part. On

Other Posts

Fill Your Customers in About Total Vehicle Filtration

If you’ve ever wondered what one of the biggest threats to a vehicle’s engine is, the answer is microscopic particles. If these tiny specs of dirt and dust aren’t filtered properly, they will quickly accumulate inside the engine, which can cause significant damage to many parts. Worse yet, this can lead to complete engine failure.

A Closer Look: Advanced Driver Assist Systems (ADAS)

Advanced Driver Assist Systems (ADAS) Overview: Advanced Driver Assist Systems have been quite the industry buzz over the last several years. We have seen new business opportunities arise, and even a new segment of mobile technicians focusing on ADAS calibrations. While ADAS may seem relatively new, automotive service professionals have been servicing Driver Assist Systems

FRAM® Provides Next-Level Engine Protection for the Summer

For many people, road trips are an enjoyable summertime tradition. Whether you’re taking the family outon vacation, traveling for sporting events, or just hitting the road for some mind-clearing relaxation,summer usually means miles. Since 1934, Pros and DIYers everywhere have relied on FRAM® to get the most complete engineprotection. When it comes to making sure

Going the Extra Mile(s) with Iridium Spark Plugs

Advanced spark plugs designed to improve fuel efficiency in today’s engines. Helping customers choose the right spark plugs is more important than ever. When it comes to late model vehicles in particular, shop owners and technicians understand that improvements in spark plug design, metallurgy and technology can help maximize the performance and fuel efficiency of