Help, 98 Accord hard on gas / bad idle

Discussion in 'Accord' started by nordsy, Dec 26, 2006.

  1. nordsy

    nordsy Guest

    Hello all,
    I have a 98 Honda accord 4cyl vtec 125k - using 87 octane fuel. It
    started having high consumption of gas around 122k, check engine light
    was intermittently coming on. AutoZone hooked up the computer and it
    stated that the primary O2 sensor was faulty, well I had it replaced
    and no change. Took it back and their computer still reported the
    same thing, So I then took it to the Honda dealer, they told me the
    catalytic converter was going bad and was starting to plug up. Anyways
    they wanted about 780.00 to replace it with. Upon talking with other
    people in the industry I guess this is a very rare condition, so I
    opted not to replace it and just replace the O2 sensor that goes into
    the catalytic converter. Again this did not solve the high gas
    consumption and or the check engine light. Also the guy that replaced
    the O2 sensor did an exhaust compression check and stated that the
    catalytic converter is not plugged, he believes it’s just fine.
    Also when the check engine light is on, the idle is weird.. What
    happens is; When stopping and or if the car is coming down from its
    RPMs the engine almost dies then it seems to recover normal idle at
    800 RPMs. So if I rev up the car and let off of the gas, the RPM’s
    drop down to 100-200 and about 4 secs later it recovers.
    Anyone have ideas to why it is consuming so much fuel -I am getting
    around 20mi where normal is 28-30 (tailpipe is very clean, no leakage
    anywhere) and what is going on with the idle?
    Otherwise the car sounds really good and idle is smooth after it
    recovers. Before I bought it, @ 110k the maintenance was all
    completed – Timing belt, all belts, water pump, spark plugs, and
    battery.
     
    nordsy, Dec 26, 2006
    #1
  2. nordsy

    jim beam Guest

    check and see if the timing belt has skipped a tooth. since you've had
    this changed, it's very common for inexperienced techs to get the
    tension wrong and the belt will skip sending both the valve timing and
    the ignition timing out. this will cause incomplete combustion and bad
    sensor readings. also make sure the sensor is genuine honda - honda
    ecu's don't like bosch sensors too much for some reason.

    other than that, make sure that the distributor cap/rotor are new and
    honda, and that you run a couple of tanks of injector cleaner through it.

    when you've checked the belt and the components, take it out on the
    freeway and take it on a long hard drive for at least a couple of hours.
    find plenty of hills and use the gears to keep it up near the red line
    [it's a honda - it can take it]. this will burn out deposits from the
    catalyst and the combustion chambers. it will also give the injectors a
    chance to open up and stop leaking.

    yes you can use aftermarket catalysts, but don't use universal, use one
    of the made to fit versions. but don't change it until you've
    eliminated /everything/ else.
     
    jim beam, Dec 26, 2006
    #2
  3. nordsy

    Elle Guest

    Try a bit more in the tuneup area and also all the items at

    http://home.earthlink.net/~honda.lioness/id11.html

    Take the OEM parts advice seriously. BTW, would you please
    clarify which (fwd or aft of cat converter?) O2 sensors were
    replaced in this car, and were the new ones OEM?

    For the odd idle behavior, pay especial attention to the
    advice about topping off the coolant.

    At times all that is needed is a new set of OEM ignition
    wires.

    This newsgroup has seen a plugged cat converter or two in
    the last couple of years. It's not that rare.
     
    Elle, Dec 26, 2006
    #3
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