Tough stuff, Bucky

On those not-quite-infrequent-enough occasions when I have to have automotive repairs done, I search for TSBs: Technical Service Bulletins, those handy addenda to the factory service manuals that cover the problems that weren’t necessarily anticipated beforehand. (My subscription to Alldata’s online manual includes all the latest TSB updates.) Sometimes — not always — they’re the next-best thing to a recall, because they indicate that the automaker knows about this problem and has a fix that doesn’t require hours upon hours of hyperexpensive diagnostics: if A and B, then perform C.

There exists, in fact, a TSB for Gwendolyn’s minor indigestion: if code set=P0420 and drivability issues=none, then there are two choices for C: if the ECU is not at current release level, flash its little EPROMs; if the ECU is at current release level, replace one particular oxygen sensor (of four) and the front pipe assembly.

It was the latter in her case, so she’s getting new hardware. The front pipe, I regret to say, contains all the pre-catalytic-converter stuff, and costs more than the actual cat. (And since it’s not the actual cat, it’s not covered under the Federal emissions warranty, and yes, I took this up with the service manager; force of habit, I suppose.) Still, I feel vaguely better paying for real live parts than I would paying for a lot of part-swapping and other guesswork.



  1. Dr. Jan »

    11 September 2006 · 8:44 pm

    You are simply a genius. When stuff like that happens to me, I have to get a new car…lol

  2. CGHill »

    11 September 2006 · 9:24 pm

    P0420, incidentally, means “Catalyst System Efficiency Below Threshold (Bank 1).” To translate into English translated from Japanese:

    “The ECM monitors the switching frequency ratio of front and rear heated oxygen sensors. A warm-up three way catalyst with high oxygen storage capacity will indicate a low switching frequency of rear heated oxygen sensor. As oxygen storage capacity decreases, the rear heated oxygen sensor switching frequency will increase. When the frequency ratio of front and rear heated oxygen sensors approaches a specified limit value, the warm-up three way catalyst malfunction is diagnosed. Malfunction is detected when warm-up three way catalyst does not operate properly, warm-up three way catalyst does not have enough oxygen storage capacity.”

    And a big orange light glares at you from the instrument panel.

    Bank 1, incidentally, generally refers to the group of cylinders in front (for a sideways V-engine, such as Gwendolyn’s), not to the place you go to apply for a loan to have the oxygen sensors replaced.

  3. Q »

    23 October 2006 · 9:50 pm

    So how much money was Gwendolyn going to be put out of. My car which is a Mazda Millenia 2.3L V6 is doing to same thing.

  4. CGHill »

    24 October 2006 · 6:26 am

    I believe the final toll (I don’t want to look at my Visa bill, it’s too scary) was $1,178.

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