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Replacing oxygen sensors, is it actually needed and worth it?

Discussion in 'General Viper Discussion' started by Roy, Jul 12, 2014.

  1. Roy

    Roy Enthusiast

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    Hi guys,

    I was browsing the internet and found on Roeracing that they advise to swap the oxygen sensors every 3-5 years because they would have carbon build up on them which makes them let the engine run richer, which causes a non necesarry rich burning engine.

    http://www.roeracing.com/ProductCart/pc/Oxygen-Sensor-03-06-Viper-SRT-10-Downstream-208p557.htm

    This is the part I mean, do you guys do this on a regular basis and do you notice any difference? I guess that mine could be as old as the car because it isn't a standard maintainance procedure as far as I know, so Dutch non specialist Dodge dealers might just forget these kind of things.

    One thing I do know is that I burn a lót of fuell:D
     
  2. GoCanes1

    GoCanes1 Enthusiast

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    Just replaced mine from Roe, was definitely needed.
     
  3. Roy

    Roy Enthusiast

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    how do you mean? Do you feel any difference while driving or in fuel consumption or needed because they looked blackish?
     
  4. speedracervr4

    speedracervr4 Enthusiast

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    The O2 sensors will become "lazy" and not cycle as fast creating a rich condition. You probably will not notice it without having a wideband installed. I was able to notice one of mine start going bad because it would peg rich in closed loop (for a short period) on my wideband gauge.
     
  5. GoCanes1

    GoCanes1 Enthusiast

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    Yes, I went to have mine tuned and ran into several problems including running rich. Both banks wanted to add fuel when it was not needed.
     
  6. luc

    luc Enthusiast

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    100% BS.

    To start, time has nothing to do with OS getting "bad". If that was the case manufactures/dealers will have to rotate/trash their inventory every 3 to 5 years??????????????
    Mileage do have an impact on OS but usually they are good for 100K miles at a minimum.
    So let see, carbon build-up make them send the wrong signal to the engine computer?
    If that is the case, the signal sent will be outside of design parameters and your "check engine" light would come on.
    The only logic behind such a statement is to sell more products.
     
  7. speedracervr4

    speedracervr4 Enthusiast

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    Seen it with my own eyes without a CEL. The older gen Diagnostic system is not very sensitive. Sean does not make a lot or anything on OEM parts..
     
  8. Roy

    Roy Enthusiast

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    The reason for asking mostly was because about every car in the world has these sensors and although I owned lots of (sports)cars I have never ever heart someone advising to replace them before they break down...I understand that they will be going bad in a certain period of usage, but my logic sense says they have a build in margin and whenever it stays within the margin...it's ok and after it, it should light the check engine light...or did Dodge made this margin too big with this car?
     
  9. Fangs10

    Fangs10 Enthusiast

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  10. MoparMap

    MoparMap VCA National President Venom Member

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    As mentioned previously, they'll just get a little slower responding over time. Assuming a stock system, they're narrowband sensors, so they're more or less just a switch that tells the computer the mixture is rich or lean, but not by how much (they do to a small degree, but not near as effectively as a wideband). At cruise, the output looks like a wave that will cycle rapidly from rich to lean and back to rich, effectively telling the computer that the engine is running close to ideal. As the sensors wear and get coated with exhaust buildup this switching wave will get slower and slower, so the computer takes longer to correct the mixture. It's important to note that this only really makes a difference at cruise though. At higher engine demands, the computer ignores the sensors and runs "open loop". Narrowband sensors are only used in "closed loop" operation, which more or less means steady state style conditions (idle, cruise, very light engine loads). Life on them tends to be 60k-100k miles in a stock system, custom tunes might change that but I can't say how much. I've replaced them on several cars (not necessarily Vipers) around the 100k mile mark as they started tripping check engine lights, so that seems to be a reasonable number for their lifespan. Replacing them earlier might keep your engine running more efficiently, but I would certainly agree that it's a mileage and run time issue, NOT a shelf life thing. If you're driving a gen 4, the computers on them are so picky due to emission standards that you probably don't need to replace anything until a check engine light goes off. If changing an air filter or muffler is enough to set those off I have a feeling the O2 sensors have a pretty slim margin as well.
     
  11. Fangs10

    Fangs10 Enthusiast

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    So in layman's terms, if it ain't broke don't fix it.
     
  12. MoparMap

    MoparMap VCA National President Venom Member

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    Haha, well put. The main takeaway being that changing it before it trips a code likely won't make much difference in performance or economy.
     
  13. Alabaster Mamba

    Alabaster Mamba Enthusiast

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    Actually, O2 sensors will get clogged with soot and still not throw a CEL. They cause more fuel to be used, thus causing a rich condition. And your gas mileage suffers. Yes, they are good for 60k-100k miles until they fail. But that is failure, not causing degraded performance. Think of it like a MAF as well. Does the placement of your MAF affect performance? Sure does due to cooler/warmer air. The point is, that O2 sensors can make the car run rich even without setting a code. Think about a clogged fuel filter. Your car still runs but does so sluggishly. Does it throw a code? No. But replacing it with a new one sure does improve performance. Same goes for plugs. The new platinum plugs are great and are supposed to last a lifetime. But when they lose the little puck, do they throw a code? No. An even better example is the use of copper plugs. When they get old and have corroded, do they still work? Yes even though the electrode is covered in soot and worn down. You put new plugs in and the car responds accordingly.
     

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