How to Bench Test the o2 Sensor

[bang2568]

I have a 2003 vmax 150 HPDI. I have removed and cleaned the oxygen sensor, sniffer tube and housing. Before I re-install the o2 sensor, I want to bench test it to make sure it is operating properly.

Is there a procedure to test to sensor while it is off the motor? I was wondering if you could use a battery to supply power to the sensor and test the voltage.

If you cannot easily test the sensor off the motor, can an auto parts store or marine service dealer test it for me?

Thanks in advance for the help.


Todd

[craigs06]

There is a thread on here, I don't know how to find it. Someone will be along soon.

[craigs06]

oops

[BuzzB8]

http://www.boatsetup.com/O2sensor.pdf

[bang2568]

Thank you all for the feedback. I have the pdf in the link above.

1) The test procedure requires a harness. Can the test be done without the harness? If Yes, How? What color wire do I read?

2) How can the test be done without applying power to the sensor? How does it generate a voltage without a voltage source?

3) I have read the responses that using a torch will damage the sensor. What is the conscensus on this?

Thanks again for the advice,

Todd

[craigs06]

works like a thermocouple, heating dis-similar metals causes a millivolt level of voltage to be produced. This voltage can be measured. You can use a test lead to push in the plug along side the wires. I think if you read the how to file, you'll see that a propane torch is good to use, just heat less than 30 sec

[ghind]

Todd,

DO NOT use the torch method, Yamaha retracted this a LONG time ago. It only takes a few minutes to put it back in the boat and test it this way.

It would be wise to have the harness but you can push your multimeter prongs into the back of the plug and measure voltages directly.

I don't know of any way to bench test it but google may help - it is very similar to any normal o2 sensor.

Greg

[bang2568]

Thanks for the info. The sniffer, sensor and casing are clean. When I was installing them back into the block, I found that the hole between the block and sniffer was completely closed with carbon. I cleared this out and hopefully this is the reason why I can only get 5100 rpm’s at WOT.

I have also replaced both fuel pumps, VST filter and the regular fuel filter.

Thanks for the help! This motor was new to me in the spring. I wish I would have done all this when I picked it up, but it just takes time learn a new motor.

Thank You to everybody on this board for the help getting me dialed on the “Need to Knows” . I am not confident that I can maintain this for many years .