honda accord car recently extremely high gas mileage, step on the throttle response is slow, is not very maddening?Don't be in a hurry to send it to the repair store to spend a lot of money, it is likely that the small part called " o2 sensor honda accord " on the exhaust pipe has a problem.If it doesn't work properly, the engine will spray oil blindly.Today teach you a few ways to use a multimeter can be their own initial judgment, both to save heart and money.

01 "o2 sensor honda accord" What does it do?

Simply put, it is like the "nose" of the engine, mounted on the exhaust pipe to detect the oxygen content in the exhaust gas.It then sends information to the engine control unit (ECU) as to whether the current air-fuel mixture is too rich or too lean, so that the ECU can adjust the injection volume in time to maintain the air-fuel ratio as close as possible to the ideal 14.7:1 - the key to ensuring combustion efficiency and emissions compliance.
If this "nose" fails, you will notice:
The malfunction indicator on the instrument panel may come on (check for the presence of the malfunction codes P0130 to P0167).
Fuel consumption has inexplicably increased and your wallet is deflating fast.
The vehicle does not accelerate as smoothly as it used to, feels underpowered, and may shake at idle.
The smell of the tailpipe may be abnormal, with a pungent odor or a smell similar to rotten eggs.

02 Test yourself with a multimeter

First confirm your "nose" type
Before you get started, unplug the o2 sensor honda accord plug and check how many wires are there:
4 wires: this is the one with the heating function.Usually two wires of the same color are responsible for heating, one signal wire (usually black) and one ground wire (usually gray).
2 wires: this is the older type, no heating, only signal and ground wires.
The color of the wires may vary from model to model, so if you are really unsure, check your vehicle manual!Also, again: the exhaust pipe is extremely hot!Be careful when operating!
Check if the "heater" is working properly
Measure the resistance (turn off the engine and unplug it):
Set the multimeter to theResistance (Ω), locate the two heater wires and connect the two pens to ensure good contact.Under normal conditions, the resistance value should be between 5 and 25 ohms.If the resistance value is infinity (open circuit) or close to zero (short circuit), the heater wire is damaged.
Measure voltage (start engine and plug in):
Set multimeter to 20V DC.Measure the voltage from the heater wire to ground, which should be about 12V.If there is no voltage, first check if the relevant fuse or line is disconnected.
Check for proper "signaling"
Keep plugs connected and allow engine to warm up sufficiently (idle for 5 - 10 minutes).Set multimeter to 2V DC.
The red pen connects to the signal wire (usually black) and the black pen is grounded (find a clean metal part).
for readings.Normal oxygen o2 sensor honda accord, the voltage signal will change rapidly between 0.1V and 0.9V, about seven or eight times in 10 seconds is normal.
Voltage is constantly below 0.45V: mixture is too lean.
Voltage constantly above 0.45V: mixture too rich or o2 sensor honda accord "poisoned" (e.g. leaded gasoline used).
Voltage is essentially unchanged: o2 sensor honda accord is aged or completely damaged.
Test it: unplug a vacuum hose (to simulate air leakage), the voltage should quickly drop to 0.1 - 0.3V. Quickly cover the air inlet (to simulate thick oil), the voltage should quickly rise to 0.6 - 0.9V. If there is no response?Then it's probably really bad.
Check the wiring by the way
Use a multimeter with a resistance setting (or a beeping setting) to test the wiring harness for conduction and a short to ground.A broken wiring harness can also cause an abnormal signal.

03 What to do?

If the heating resistance is abnormal or there is no change in the signal at all, you basically need to replace the o2 sensor honda accord with a new one.If the signal is persistently high or low, it may be caused by carbon buildup or "poisoning", you can try to use a cleaning agent (but if the internal components are aging, cleaning won't help), and replacing it with a new one is the least expensive.Repair the wiring if there is a problem with the wiring.

04 Tips

Again: be careful of burns!Use a special socket to remove and install the o2 sensor honda accord to avoid damage.Apply some anti-seize to the threads of the new o2 sensor honda accord for easy removal next time.Once the replacement is complete, use a diagnostic to clear the fault codes and allow the system to relearn.