When it comes to vehicle maintenance, various components whose functions simply aren’t understood by the average car owner, especially when it comes to the inner workings of the engine, take the oxygen sensor (O2 sensor), for example.
You’ve probably heard of it, but do you know why they’re so important and how will a bad O2 sensor cause misfire and affect your engine’s performance? Let’s find out.
Article Summary
What is An O2 Sensor?
O2 sensor, more often known as an oxygen sensor, is an important part of a vehicle’s exhaust system. It collects data from the amount of oxygen in the exhaust gases and conveys it to the vehicle’s engine control unit (ECU).
The ECU then calculates the correct proportions of air and fuel and sends a command for ignition. In this particular way, the O2 sensor makes certain that the system burns the fuel in the correct proportions.
A failing O2 fuel economy, increased emissions, and possible make the catalytic converter bad.
Symptoms of A Bad O2 Sensor
Before we go on and talk about what happens to the engine if your O2 sensor is not up to the job, here are the most common symptoms of a bad O2 sensor:
Check Engine Light: One of the most obvious symptoms is that the check engine light flashing on the dashboard.
Poor Fuel Economy: If the O2 sensor malfunctions, the computer may implement an incorrect air fuel mixture, wasting fuel.
Rough Idling: The engine may run roughly or inconsistently when idling.
Higher Emissions: If an O2 sensor becomes defective, the car will start producing excessive quantities of harmful gases in harmful exhaust gas, and hence, it will fail an emissions test.
Engine Performance Issues: You might notice a loss of power or hesitation during acceleration.
Will A Bad O2 Sensor Cause Misfire?
Yes, a bad O2 sensor will indeed cause engine misfires. Here’s how:
Poor Air Fuel Mixture
A failed or out of range O2 sensor can keep the engine’s fuel mixture too rich or too lean, either of which can cause misfires.
An excessively rich mixture burns most of the fuel in the combustion chamber and can flood that small, sealed space.
Too lean of a mixture produces too little resultant pressure to keep the engine combustion on a downward cycle.
Disruption of a feedback loop
The O2 sensor is designed to pull in live and dynamic information about the oxygen content of the exhaust feeds.
That information into the ECU on a continuous basis, tracked over time, allowing the EFI system to make split second, intelligent decisions about adjusting the air and fuel ratio.
If the sensor stops working (which it will, as a normal part of its working life), it disrupts the feedback loop, making it impossible for the ECU to adjust the air and fuel ratio, resulting in misfiring.
Catalytic Converter Destruction
If the faulty O2 sensor goes unchecked, other components, such as the catalytic converter, might start to be affected.
A faulty catalytic converter can contribute to even more severe engine performance issues, such as a misfire.
Diagnosing and Fixing the Problem
If you suspect the culprit is a faulty O2 sensor that’s causing your engine to misfire, here’s what you should do.
OBD-II Scanner
Plug an OBD-II scanner into the port, and if an error code is detected, typically P0130 to P0135, the problem is now well defined. It could be the circuit for the O2 sensor (P0130) or the heating element for the O2 sensor (P0135).
Look at the Sensor
Inspect the O2 sensor visually for cracks, damage, or contamination. It could very well be a loose, damaged, or corroded sensor plug causing issues rather than the sensor being bad.
Replace the Sensor
If the O2 sensor is confirmed bad, the best fix is to replace it. Use a quality replacement sensor.
Look for Other Problems
Faulty spark plugs, ignition coils, or fuel injectors can also cause misfires.
Prevention for Bad O2 Sensor
You are well aware that proper care for your O2 sensors will maintain your engine’s best performance and save you time. Therefore, keeping these sensors in good condition always leads to better fuel efficiency and fuel savings.
In my opinion, there are three preventive methods for stopping O2 sensor problems and helping you avoid O2 sensor removal. They are.
Regular Maintenance and Inspections
Routine maintenance, including a full mechanical inspection, will help avoid the contamination of an O2 sensor. This includes the checks outlined in your owner’s maintenance schedule.
Schedule Routine Inspections: Schedule check-ups with your car mechanic at regular intervals to check the O2, as well as all essential car parts.
Using Diagnostic Tools: Often, when checking for issues that can affect O2 sensors, the vehicle’s computer can write an error code for the O2 sensor that can be read with an OBD-II scanner during periodic checks.
Check Connections: Check all connections to the O2 sensors for tightness and corrosion. A loose or corroded connection can cause a bad signal or no signal at all from the sensor.
Use High Quality Fuel and Oil
For this reason, manufacturers recommend only good quality fuel and oil (basically made of synthetic components). Otherwise, fuel or oil residuals could block the O2 sensor, requiring replacement.
Choose Quality Fuel: Use only good gasoline you know from viable gas stations. Never fuel with bad fuel containing high percent added ethanol or other impurities that can damage your O2 sensor.
Regular Oil Changes: Please stick to the manufacturer’s recommended oil changes. Use the highest quality oil and match it appropriately to the vehicle’s specifications.
Clean oil keeps your engine healthy. A polluted exhaust system will dump mercury as ash.
Additives Caution: Use fuel additives carefully. Your vehicle’s manufacturer recommends certain additives, and others can damage O2 sensors.
Monitor and Address Engine Performance Issues Promptly
While the root of this issue appears to be the PCBs merging of exhaust with oncoming fuel, its triggers are what matter here: a faulty ignition coil, water in the fuel, an undersized air filter, or a misfiring engine.
If you notice your car’s performance changing and start to address the issues before they become complex, potentially costly O2 sensor issues, it might just be your saving grace.
Pay Attention to Warning Signs: If your check engine light is on, your vehicle idles roughly, doesn’t accelerate well, loses power, runs poorly, doesn’t accelerate as it should, has a “hot” smell coming from the exhaust, or drinks fuel faster than normal, you should have your O2 sensor checked.
Timely Repairs: If you or a scan tool see such codes, investigate the drop in fuel economy and have any recommended O2 sensor repairs made right away.
Preventive Cleaning: Clean the exhaust system and the O2 sensors regularly, ideally every 5,000 to 10,000km, depending on your local driving conditions. A well maintained exhaust system and clean O2 sensors will provide more accurate readings.
If you follow these preventative steps as part of your routine vehicle maintenance, you can help keep your O2 sensors in top shape, boosting your car’s engine performance as well as gas mileage.
FAQs on Will A Bad O2 Sensor Cause Misfire
What Are the Main Symptoms of A Bad O2 Sensor?
The check engine warning light can come on, and the car does not run as well as it once did. It can throw off the fuel mixture, making the car burn more fuel than necessary. The car could get sluggish or jumpy while driving, have a harder time accelerating, lose power on steep hills, give off dark exhaust smoke or foul odors, and stall out when the engine is too cold or when you come to a complete stop.
How Does A Bad O2 Sensor Cause Engine Misfires?
A bad oxygen sensor could cause an engine misfire due to the loss of air/fuel mixture feedback to the ECU. (If an oxygen sensor fails, the air fuel mixture can be too rich or too lean, and neither of those would be able to burn properly, so you get misfires. Also, the air fuel mixture is continuously monitored by the ECU. If the oxygen sensor isn’t working properly, the ECU has no feedback to use for making adjustments to the air fuel ratio.)
Can I Drive with A Bad O2 Sensor?
It is possible that you could continue to drive the vehicle while it has a bad O2 sensor, but you definitely shouldn’t. If the O2 sensor fails or starts to fail, it will allow too much fuel to be injected into the engine, leading to lower fuel economy. Over time, it can also cause an increase in emissions and possibly damage the catalytic converter. Driving the vehicle while the O2 sensor is bad can lead to engine misfire, stalling, and a variety of other problems that will require time and money to resolve.
How Often Should O2 Sensors Be Replaced?
O2 sensors are usually replaced every 60,000 to 100,000 miles, depending on your particular make and model. Please refer to your automobile’s maintenance schedule as well. It is recommended that you periodically check the O2 sensors and replace them as necessary to maintain the best possible engine function.
What Other Problems Can A Bad O2 Sensor Cause?
A bad O2 sensor alone may cause one or more of the following symptoms: engine misfires, poor fuel economy, excessive emissions, rough idling, difficulty involved in passing emissions tests, and may eventually ruin the catalytic converter (very expensive to repair or replace).
Conclusion
A bad O2 sensor is capable of throwing a code in your vehicle, causing it to misfire because it interferes with the feedback loop between the air fuel mixture, spark, power stroke, and oxygen detection. Act quickly if you identify the symptoms of a failing O2 sensor.
The earlier you deal with the problem, the better you can prevent and protect your vehicle from further damage.
Keep up with regular maintenance and replace faulty parts as soon as they somehow go bad, wear out, or need to be replaced.
