210K miles on 2008 Tahoe. Replacing O2 sensors

[wjburken]

So if I never get a MIL regarding the sensors, it’s safe to say they are fine for now? If I were to get a MIL I’d probably replace them all.

That’s what I would do. My 2007 Denali with the 6.2L went 300K in original O2 sensors.

 

[OR VietVet]

Of course, totally your call. Lots of fuel mileage can be wasted before the readings get out of parameters and turn on the MIL. Plus, by that time, catalytic converters that are good now, may well get damaged before the MIL comes on. I consider oxygen sensors as a maintenance item. I never wait till I have a misfire to change plugs and wires. I never wait till I am dead alongside the road before I replace the fuel pump, fuel filter and relay. I never wait till I have a no crank situation before a battery replacement. Again, your call.

 

[trailblazer]

Seems like if “lots of fuel mileage will be wasted” then there should be a MIL or noticeable reading.

 

[OR VietVet]

I am talking about accumulative over time. If it gets drastic and out of parameters then yes, the MIL should come on. If is gradual and keeps the MIL light off but is still doing damage to the cats with the wrong stoichiometric ratio, air fuel mixture of 14.7 to 1, but may not be far enough out of parameters to turn that light on. We have had members complain of loss of power and was related to bad cats but they never did see a light on. I guess I am just paranoid about that. I would rather replace sensors when I know the cost and can plan it instead of having to do sensors and cats and be surprised. I don't run shops anymore so I am not selling to anyone. I am just offering my opinion.

 

[Seamus]

They should be changed at 100K. Yes expensive but your paying for it in fuel. Also if out of spec they can hurt your cats. Which of course is more expensive. I just did all 4 on mine at 94K as 1 was bad. I too bought from rock auto and bought AC Delco. Happy I did. They have the exact length wire and GM clips that hold it in the stock spot perfectly.

 

[OR VietVet]

They should be changed at 100K. Yes expensive but your paying for it in fuel. Also if out of spec they can hurt your cats. Which of course is more expensive. I just did all 4 on mine at 94K as 1 was bad. I too bought from rock auto and bought AC Delco. Happy I did. They have the exact length wire and GM clips that hold it in the stock spot perfectly.

Plus you could plan on the repair and the cost. No surprises. Plus, great protection for the expensive cats.

 

[pacem]

Of course, totally your call. Lots of fuel mileage can be wasted before the readings get out of parameters and turn on the MIL. Plus, by that time, catalytic converters that are good now, may well get damaged before the MIL comes on. I consider oxygen sensors as a maintenance item. I never wait till I have a misfire to change plugs and wires. I never wait till I am dead alongside the road before I replace the fuel pump, fuel filter and relay. I never wait till I have a no crank situation before a battery replacement. Again, your call.

--------------------------------------------------------------------------- I like that approach.

 

[swathdiver]

Use your scan tools to measure the health of the O2 sensors. If they're moving within spec, there's no benefit to you in replacing them. Again, I would caution against using any other O2 sensors other than GM OE or ACDelco Professional.