Does anyone know how to test an Oxygen Sensor?? And if it's bad, where is the best place online to buy one?? Muchas Gracias!!

 

Welcome to the board man!

Not sure how to check if its bad...but if you have a Check Engine Light on and are noticing performance decreases then its most likely bad...I would only go stock for the 02 sensor.

Fink

 

You can either probe the voltage when the engine is running or get an OBD reader like mine which will give you the output of all the sensors onboard the vehicle. Check my sig for details.

I would get an OEM sensor but there are some aftermarket available online too.

 

use "search"...... somebody put up a website earlier on where to get 02 sensors for cheap!

 

OxygenSensors.com.

Get the 'universal' O2 sensor, then plug it in where the stock one was, using the stock hardware.

 

whats the voltage reading suppose to be on a o2 sensor??

 

A good working O2 sensor should have a voltage that fluctuates between 200 and 800 mV. If it fluctuates in a narrower range (400 to 600mV), it means it's going bad.

remember to test the O2 sensor under normal operating temp, when under closed loop.

oh yeah, using an Analogue Multimeter would be better because digital multimeters can be slugish because of their low sample rate.

 

I can't say I agree with this info at all. Yes, the sensor should be between 0 and 1volt anything outside that should trigger a CEL. An engine management system can fluctuate quite a bit or barely at all, so just stating 0.4 to 0.6V, you may throw out a good sensor. It also depends on which sensor you are looking at. The sensor in front of the cat varies alot more than the one behind the cat. A truly malfunftioning O2 sensor will almost always trigger the CEL. You can still replace and see if it helps as well.

I have never seen an analog meter beat a digital one. Maybe the older digitals were slower but I have never had trouble capturing the variation in voltage on a DMM.

If you really want to see the readout from the sensor well use the OBD II reader in my sig.

 

This info was taken from the Toyota Service Manual...

Have you ever compared the readings from a Digital and an Anologue multimeter? You can't beat the response of an anologue multimeter.

Good to see a french(?) canadian on the board!

ps: he might not have OBDII, (started in 96) so he won't get a
check engine light

The one behind the cat is TOTALLY irrelevant to closed loop a/f control. It will only compare the reading with the front one to verify if there's more o2 (in %) present, so less unburt hydrocarbons...