How Do You Know Which 02 Sensor to Replace

DIY Difficulty Level: Intermediate, could be easier or harder depending on the vehicle
Fourth dimension Required: one to two hours
Tools & Materials:
- New oxygen sensor
- Wrenches and sockets
- Oxygen sensor socket (if your sensor is difficult to reach with a wrench)

What Is an Oxygen Sensor?

The oxygen sensor (commonly referred to as an "O2 sensor") monitors how much unburned oxygen is in the exhaust every bit the frazzle exits the engine of your vehicle.

Typically, there are 1 or ii sensors in forepart of your catalytic converter and 1 backside it. Comparing data from before and subsequently the catalytic converter as well tells the reckoner how well it is working and if there are any issues with your emission system besides.

Past monitoring oxygen levels and sending this information to your engine'south computer, these sensors let your car know if the fuel mix is running rich (not plenty oxygen) or lean (too much oxygen). Proper air-fuel ratio is disquisitional to keeping your car running as smoothly every bit it should be.

Exist certain to read our in-depth guide to oxygen sensors for more than information.

Is Information technology Prophylactic to Bulldoze with a Bad Oxygen Sensor?

When an oxygen sensor fails, there are a variety of diagnostic trouble codes (DTCs) that can popular up. Most of the time, a faulty oxygen sensor will event in a check engine calorie-free accompanied with a mistake code that yous can read with an OBD2 scanner like FIXD. Based on this fault lawmaking, it will bespeak to how it failed and and so motility forward with the diagnosis.

Continuing to bulldoze with a faulty oxygen sensor can cause the engine to run rough, and potentially cause a lack of power or even engine damage. The check engine light being on volition likewise cause you to neglect an emissions test if you live in an area that includes them in auto inspections.

Whether it's worth replacing an oxygen sensor yourself or paying a shop to do it depends on how difficult it is to admission the sensor. My van's sensors are easy to attain from inside with the "doghouse" over the back of the engine removed, so information technology's a no-brainer to replace it myself. On other cars, the sensor may be crammed between the peak of the exhaust pipe and the floor of the car, and/or crave a pregnant dismantling of your exhaust arrangement to attain. If it's too hard for you, accept it to the shop.

When to Replace an Oxygen Sensor

The oxygen sensor is non a routine maintenance detail. They practice fail from fourth dimension to fourth dimension, though, triggering a check engine light. Employ an OBD2 scanner similar FIXD to determine the cause of the check engine light. If the problem code indicates bad data from an oxygen sensor, it's fourth dimension to replace it. Dissimilar other items, you don't demand to supercede all of the oxygen sensors at the same time when 1 fails.

What Are Common Symptoms Indicating You Need to Replace an Oxygen Sensor?

Symptoms of a faulty O2 sensor may include the post-obit:

Cheque engine light, frequently a P0420 code
Lean or rich running condition
Poor acceleration
Engine hesitation
Black fume from tailpipe (rich running condition) black smoke is backlog fuel exiting the exhaust
Rough idle
Vehicle stalling out
Reduced fuel efficiency

Go along in Mind

Simply considering the trouble code(s) y'all scanned signal a problem with the oxygen sensor doesn't mean the sensor itself is automatically bad. It might operating correctly and simply doing its chore of telling you lot something is wrong in another part of your engine. For example, a Ford technical service bulletin says that for several codes associated with the oxygen sensor, the first thing you lot should check is the PCV valve, not the sensor. Research your particular brand and model, cantankerous reference any codes you lot get, and make sure a bad sensor is really the problem before replacing it.

If in doubt, it's certainly worth taking your motorcar to a shop for a professional diagnosis. They have the tools and knowledge to make up one's mind whether your sensor is bad or if something else is incorrect with your auto.

How It'southward Done

Step 1: Diagnose the bad oxygen sensor

Your car has at least two oxygen sensors, possibly more depending on your engine. Use the Live Gauges characteristic of FIXD to watch the information coming in from your sensors in real-time. In this example, sensor i is fluctuating normally as it should, but sensor 2 appears to exist stuck at 0 volts. This would indicate that the upshot exists with sensor 2. For a detailed description of the diagnosis process, read our commodity all almost oxygen sensors.

Again, research your item vehicle, and make certain there isn't another problem that the sensor is correctly indicating, rather than assuming the sensor itself is bad. If everything else is fine and yous are confident that the sensor is bad, then supplant information technology.

Footstep ii: Unplug the sensor

Unplug the oxygen sensor from its wiring harness. This volition let it to plough freely when you remove it from the exhaust pipe.

Step three: Lubricate the threads

The oxygen sensor screws into your exhaust pipage just like a screw or a spark plug. Numerous cycles of heating upwardly and cooling downwards crusade the metal to expand and contract, which could brand the sensor fit tightly. This area is also prone to rust, making matters worse. Spray the area with penetrating oil similar WD40 or PB Blaster, then allow information technology sit for a while. This will make removing information technology easier.

Step 4: Remove the sensor

If you take the space, as shown higher up, you tin can use an open-end wrench to remove information technology. In tight quarters, yous might need to utilize an oxygen sensor socket. This is a special socket with a slot to put the wire through and so you can slide it down over the sensor. Your socket wrench or extension attaches to an offset flange to give you lot better leverage on it. Do what information technology takes to go the old sensor out.

Step 5: Install the new sensor

As the repair manuals say, installation is the opposite of removal. Screw the new sensor tightly into the exhaust pipe, and then plug it into the wiring harness.

Step 6: Clear your codes

Using FIXD, scan your trouble codes once again, then click the Clear Engine Calorie-free push button at the bottom of the screen. This will clear all of the codes and turn off your bank check engine light.

Step 7: Go for a bulldoze

As you go along to drive, your check engine light should remain off, indicating that the problem is stock-still. If the light turns back on, the sensor you replaced was not the problem after all. Use FIXD to read the codes and keep diagnosing the problem.

Merits Your Custom Maintenance Schedule

Get the FIXD Sensor and free app today for a custom maintenance schedule based on your make, model, and mileage. Never miss important maintenance again with automated maintenance alerts! Learn more than at fixdapp.com.

Recovering autocross and rails 24-hour interval enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally auto.

How Do You Know Which 02 Sensor to Replace

Source: https://www.fixdapp.com/blog/how-to-replace-an-oxygen-sensor/