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Will bad O2 sensors always trip the CEL?

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Old 04-04-2003, 01:27 PM
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Default Will bad O2 sensors always trip the CEL?

I wonder, because I got 124k mi on my '96 2.8, but I've had to replace only one O2 sensor. That one did trigger the CEL at around 60k mi.
What's the average lifespan of an O2 sensor, or does it depend on too many factors to make a guesstimate?
Old 04-04-2003, 01:28 PM
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Default Don;t know the life time...guessing it's like any other sensor..---->

but it will set off a cel.
Old 04-04-2003, 02:05 PM
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Default Hmm...

On older cars they replaced the O2 sensors every 30 k miles.

Do today's O2 sensors not necessarily go bad? I wouldn't hope so, because replacing four O2 sensors is pretty expensive.
Old 04-04-2003, 08:37 PM
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Default 147 Kmi on mine...

'97 1.8tqm and still get 27-28 mpg overall. if the maf is ok then O2 sensor is best bet. iirc they don't always cause cel.
Old 04-04-2003, 10:44 PM
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Default Heh...

I don't notice any symtoms that point at a bad O2 sensor. I was just wondering why O2 sensors used to be replaced regularly, but now we just wait for them to go bad.
Old 04-04-2003, 10:51 PM
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Default iirc a lot of O2 sensor failures were traced to...

chemical contamination. some mfg's had to change the formulas for liquid gasket matereal, sealants and such.
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