Civic '90 DX 4dr - O2 sensor and PCV valve

Discussion in 'Civic' started by precambrian, Mar 6, 2006.

  1. precambrian

    precambrian Guest

    At @140k miles, will replacing them improve engine performance at all? I
    pinched the hose going to the PCV and no clicking sound like the Haynes
    manual described there should be. The hose just collapses flat like straw in
    a vacuum. And how do you know if your O2 sensor is working the way it shoul
    precambrian, Mar 6, 2006
  2. precambrian

    Eric Guest

    Many shops replace the PCV valve at 60,000 mi intervals. Many folks also
    have success with removing the valve and cleaning it with carburetor

    Eric, Mar 6, 2006
  3. precambrian

    Elle Guest

    At 140k miles and16 years, replacing either the O2 sensor or
    PCV valve or both may improve performance. It's not
    guaranteed. OTOH, the parts are cheap enough to warrant
    replacement about now.

    Did you pinch shut the hose to the PCV valve and wait at
    least 30 seconds, listening to the click? It's not terribly
    loud, but it is noticeable. With the engine off, you should
    also remove its hose, then the valve, and inspect it. When I
    did my 91 Civic at about 138k miles, I found the valve top
    chock full of black waxy buildup.

    I would just replace the PCV valve at this point. Its
    springs, for one thing, do wear.

    One other benchmark type test: With the engine idling,
    remove the hose from the top of the PCV valve, then cover
    its top with your finger. You should be able to get the
    "click" this way, too, on your 90 Civic.

    Best prices for genuine Honda (= OEM) oxygen sensors (IIRC
    around $45 for your car):

    Best price for a PCV valve: Click on "Parts and Service," then
    "Buy Parts Online."

    With shipping, buying the PCV valve at your local dealer
    might be a better deal.

    I replaced my 91 Civic's oxygen sensor pre-emptively at 154k
    miles. I didn't notice an improvement in performance. On the
    other hand, I probably won't ever need another oxygen sensor
    for this car and so have avoided a sudden failure of the
    oxygen sensor (which admittedly is not devastating; just

    A few symptoms of a failing oxygen sensor are degraded miles
    per gallon and engine running rough. There are voltage tests
    one can do on it, too, but I think that's overkill for an
    older car.

    Only buy OEM for these parts.
    Elle, Mar 6, 2006
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