850 Non-turbo - Catalytic Converter choices?

Discussion in 'Volvo 850' started by Pat Quadlander, Apr 22, 2007.

  1. I bought my 96 non-turbo 850 with 90,000 mi a year ago, without service
    records. I replaced the time belt and spongey master cylinder.

    On Friday, it died while idling at an intersection. Earlier that day, I had
    replaced the rear brake pads, and caused some overflow spillage of brake
    fluid from the master cylinder. A little had leaked on to the electric
    connectors below the cylinder, perhaps the O2 sensor leads. I took these
    apart, wiped off the fluid, re-assembled and the car started and ran fine.
    Until I hit rush hour traffic jams and it died again at idle.

    I got to my Volvo dealer. On computer, there's 2 errors. Cyls 1 and 3 are
    misfiring, and the catalytic converter is blocked, preventing air flow for

    Since I don't have records, the mechanic suspects the spark plugs are bad,
    and/or a fuel injector is stuck open. Either of these problems explains the
    misfires. And, eventually leads to destroying the catalyst element with
    unburnt fuel. The mechanic thinks the brake fluid spillage is not
    pertinent, just coincidental.

    I bought new plugs, cables, cap and rotor and replaced these at the dealer.
    These were well overdue. The car runs fine since then, but I haven't had any
    prolonged idle tests.

    Should I stop with this? New injectors and catalytic converter are very
    expensive, especially at the dealer.

    He may be right about the cat, because of the strong sulphur smell when the
    car died - I think this is the catalytic element. But, dealer wants $1,002
    for a new cat, plus labor. Understandably, the dealer does not recommend a
    cheaper after-market alternative, but the mechanic strongly cautioned that I
    must make sure that the locations of the two O2 sensors are at the exact
    correct distance along the exhaust system.

    Some quick checking online shows aftermarkets cats for under $300, but hard
    to measure the O2 sensor ports locations. Has this group found a correct
    OEM product, other than dealer?

    I have also seen a $60 (or less) "universal" product, which is just the oval
    shaped section of the catalytic converter that encloses the catalytic
    element working part of the exhaust pipe. To install this, you have to
    torch-cut the old part out of the mid-section of the original pipe, then
    weld the new part back in its place. I don't have welding shop at home, but
    this is fairly ordinary for any muffler shop. Does this group have any good
    or bad experience with this strategy?

    Pat Q in Dallas/Ft. Worth
    Pat Quadlander, Apr 22, 2007
  2. Pat Quadlander

    John Horner Guest

    I have had good luck so far with the after-market converter I put on my
    '93 240 by Bosal. Your dealer is probably being overly dramatic about
    the importance of exact O2 sensor placement.

    I would find a good local independent Volvo shop and get an evaluation
    from them if you aren't prepared to do the work yourself. Stay away
    from chain stores and anyone who doesn't work on modern Volvo all the
    time. You don't want someone learning on your car at your expense.

    It looks like there are different parts for a California certified
    emissions vehicle vs. a standard 850. From looking online it seems that
    Volvo used several different kinds of configurations for the 96 850.
    Have a look here for some of the variations:


    John Horner, Apr 24, 2007
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