How to know when to change O2 sensors...

sunil6784

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Mar 31, 2005

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Jul 6, 2005

#1

• Jul 6, 2005

• #1

how do you test you're O2 sensors? is there a way to know if its time for them to be changed, other than a CEL ?

 

Curse

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Apr 8, 2004

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El Paso, TX

Jul 6, 2005

#2

• Jul 6, 2005

• #2

I thought you were suppose to chage them at 60-100,000 miles. Mine would make a rattleing noise, so I figured it was time to change them.

 

BlownStangGT

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#3

• Jul 6, 2005

• #3

think i read somewhere that if they were a certain color such as black then it was time to change them, its either black or white, I forget, but thats just something i thought I read

 

90mustangGT

I felt sorry for girls because

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#4

• Jul 6, 2005

• #4

Milege is an indicator. They are suposed to be changed between 50 and 90K miles. You can tell because they will either not respond correctly.

Contanimation such as oil or lead (race gas) will block coat them and they won't be able to respond because they are not exposed to the exaust gasses.

 

HISSIN50

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#5

• Jul 6, 2005

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They switch back and forth from 0.1 to 0.9 volts very quickly. As they age, they switch less quickly and lose amplitude.

Generally if one's milage drops off, that is an indication. Some solvents and such will shorten their life as well.

60K miles is a decent rule of thumb for replacement. Too bad they cost so much.

Good luck.

 

jrichker

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#6

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Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage.

Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.

 

sunil6784

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#7

• Jul 6, 2005

• #7

thanks !

 

I

Insane3D

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Jul 6, 2005

#8

• Jul 6, 2005

• #8

HISSIN50 said:

They switch back and forth from 0.1 to 0.9 volts very quickly. As they age, they switch less quickly and lose amplitude.

Generally if one's milage drops off, that is an indication. Some solvents and such will shorten their life as well.

60K miles is a decent rule of thumb for replacement. Too bad they cost so much.

Good luck.

Click to expand...

Cost too much? Brand new Bosch units are only $39...$80 every 60K-80K doesn't seem like much to me for the money saved on gas mileage...

But pretty much like you said, they slowly become less and less effective the more miles that are on them...

 

HISSIN50

"How long does it take to get help in here?

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#9

• Jul 6, 2005

• #9

Insane3D said:

Cost too much? Brand new Bosch units are only $39...$80 every 60K-80K doesn't seem like much to me for the money saved on gas mileage...

Click to expand...

Sweet, Insane is gonna buy me new O2's.

Frame of reference: Our HEGO's are expensive compared to some EGO's (though HEGO's last longer).

 

I

Insane3D

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#10

• Jul 6, 2005

• #10

HISSIN50 said:

Sweet, Insane is gonna buy me new O2's.

Frame of reference: Our HEGO's are expensive compared to some EGO's (though HEGO's last longer).

Click to expand...

Well, if you think ours our expensive...check out the ones for the 94-95's...

 

M

mike0227

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Dec 19, 2004

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Houston Texas

Jul 22, 2005

#11

• Jul 22, 2005

• #11

a scope works best! Look for time of switching between .250mv-.900mv a o2sensor should switch about 3-4 a sec if its slow than replace it! if you see a flat waveform replace it! oh yea if you use leaded gas than you will get about 3 months out of em!!!!