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Can a wide band O2 sensor be tested?

How does one test a wide band o2 sensor without hooking it up to a controller? Is it possible with a dvm? From what I've read it looks like it is not possible without an oscilloscope. Is this true?

I don't believe that a DMM will be fast enough to capture the voltage as it rises and falls according to the sensor reacting to the hydrocarbons in the exhaust flow. Keep in mind that this changes rather rapidly in a second. What are you trying to achieve? ;)

Google Image Search says you probably don't need a 'scope for a wideband: Oxygen (O2) Sensor – Narrowband vs Wideband Boost Source

Tap in to the correct wire at the ECU, drive until warm, vary the AFR with your right foot, and let us know what happens.

no or yes , depends

Quote:

Originally Posted by Carwhisperer (Post 192399)

How does one test a wide band o2 sensor without hooking it up to a controller? Is it possible with a dvm? From what I've read it looks like it is not possible without an oscilloscope. Is this true?

can not be done
do you mean AFR sensor ? even a scope can not be used .
How 5-Wire Sensors Work (Tech Edge)

with a scan tool testing an OBD2 system ...
you can follow STFT , or EQ ratio graph it if you can . STFT or Eq ratio should swing around 3 to 5 % and center on zero .

quick test is to see if STFT will settle on zero during a steady state . if no
almost always the AFR sensor is skewed or biased high or low , but an exhaust leak upstream of the AFR sensor OR after the cat or a fraked rear 02 sensor can cause rear trim to influence STFT .

an aftermarket AFR sensor in your hand
can not be tested .

the heater resistance can be tested and compared to a specification
but , that is about it .
resistance testing is about as useless as mudflaps on a sledgehammer

Quote:

Originally Posted by mwebb (Post 192489)

That's what I thought. There is a flow chart in the vx service manual where one of the results is replace LAF sensor, but that is in a chassis.

Snapon MT2500 / Solus or OTC Genesis with OBD1 Honda

Quote:

Originally Posted by Carwhisperer (Post 192567)

That's what I thought. There is a flow chart in the vx service manual where one of the results is replace LAF sensor, but that is in a chassis.

many repair shops and many individual independent Techs
have
Snapon MT2500 / Solus or OTC Genesis with OBD1 Honda software

that software will show some type of PID for fuel trim in Live data
the fuel trim should change rapidly about +/- 3 to 5% and it should center the bounce on zero fuel trim adjustment
at 2000rpm hot in neutral all accessories turned off .

for any early 90s honda .