car trouble?

Question

hi i wanted to know if there was a way you can test a oxigen sensor on a car myine is a 92 bmw 3181 can anyone help

what i meant was if you can check if its good or not because i dont want to buy a new one only if i have to

Answer 1

try and get it diagnosed.

Answer 2

You will need the following equipment:

A handheld volt meter (digital VOM)
An unlit propane torch
An oxygen sensor socket

It should take less than 10 minutes to perform a diagnostic check on most vehicles.

1. Verify the basic engine parameters, per the manufacturer's specifications for the following: timing, integrity of the electrical system (supply voltage), fuel delivery mixture performance and internal mechanical considerations.

2. Treat the rich mixture performance as follows:

a. Disconnect the sensor lead to the control unit.
b. Run the engine at 2500 rpm.
c. Artificially enrich the fuel mixture by directing propane into
the intake until the engine speed drops by 200 rpm. Or, if
you're working on a vehicle with electronic fuel injection,
you can remove and plug the vacuum line to the fuel
pressure regulator.
d. If the voltmeter rapidly reads .9 volts, then the oxygen
sensor is correctly sensing a rich mixture. But, if the
voltmeter responds sluggishly, or if it stays below .8 volts,
then the sensor should be replaced.

3. Test the lean mixture performance as follows:

a. Induce a small vacuum leak.
b. If the voltmeter rapidly drops to .2 volts or below in less
than a second, then the oxygen sensor is correctly
measuring the lean mixture. But, if the voltmeter responds
sluggishly, or if it stays above .2 volts, then the sensor
should be replaced.

4. Test dynamic performance as follows:

a. Reconnect the sensor lead.
b. Set the mixture to specification.
c. Run the engine at 1500 rpm.
d. The sensor output should fluctuate around .5 volts. If it
doesn't, replace the sensor.

Answer 3

here is a strange way of doing it but fallow carefully and you may get the answer you are looking for. with the engine warm and running, disconnect the wire that goes into the o2 sensor(only works on he non heated variety.) first take the wire and just touch the frame with it , rpm should raise a little, in essence your mimicking a lean run situation. now take that same wire with your finger tips and with the other hand touch the positive battery terminal, engine should slow down slightly.( rich condition) your body has enough resistance to cut the 14 volts to about the1 volt that the CPU is used to seeing. well now that you have, tested the the computers ability to change the mixture, with a blow torch or some other flammable gas, turn the gas on but only slightly,(don't light it) put the end close to the air inlet for the engine, if you get the same effect as you did with the finger on the battery,but it recovers, then i would presume that the o2 sensor is OK. unfortunately i don't have any tests for the heated variety.