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05 saturn catalytic converter

Should I be concerned that my cat. converter failed at 55k? The service writer had no good explanation [some stuff about bad gas some time in the past]. I also had to have the sensor that attaches to the converter replaced. That was covered under my entended warranty. There was no charge for the converter, covered because of emissions reqiurements. Just concerned about problems later on, after extended warranty expires. Thanks

The “bad gas” explanation is bogus. I don’t know why the cat failed so soon, but it wasn’t from bad gas.

Since this was covered by the emissions warranty I wouldn’t worry about it. The new converter may last the life of the car.

Thanks for the reply. I felt the bad gas excuse was “bad gas” also. I just get nervous when someone like the service adviser, who should know what he is talking about, gives me an obvious lame explanation. It lowers my confidence in the entire shop.

Since the catalytic converter is covered by warranty, I doubt that the dealer did ANY checks to determine WHY it failed. It’s too easy to throw “free” parts at problems. The oxygen sensors could have been examined for the effects of the engine burning the wrong things.

The next time the oxygen sensors, and catalytic converter, fail, it will be at the owner’s expense.

If you can find a good mechanic, ask him if he has an exhaust gas analyser and if, with that analyser, he can determine if the exhaust contains any gases from substance (such as motor oil, anti-freeze, silicone) which can harm the catalytic converter and oxygen sensors.

Kit gave you an excellent response. See if you can determine whay they failed.

Cat conveters and upstream oxygen sensors often fail because their functional surfaces get coated with carbon from burning oil or even a rich mixture. Both need to actually contact with the flowing airstream to work properly, and a coating interferes with this.

Does the engine use oil? How’s the mileage? Has it been maintained on schedule?

Oh, yeah, I don’t know why but for some odd reason whenever a shop cannot or is not willing to do the diagnostic work they blame “bad gas”. Bad gas really is pretty rare.

As well it should. Time to find a good independent mechanic and stop wasting your time with the dealer.

Thanks, I’ll take the car in next week for the exhaust gas analyzer. The service has been done on a regular basis. Oil every 3k just had trans. and coolant done. Doesn’t use oil between changes. No noticable change in mileage. I’ll keep everyone updated.

I would advise that you never put much faith into what a service writer says. Only a very few of them are mechanically knowledgeable with the vast majority having to rely on a little smooth talking and outright BS to avoid making themselves look uninformed.

Often what a service writer says will be diametrically opposed to what a mechanic might say. This is the huge disconnect between mechanic and car owner i often refer to.

No idea why your original converter failed; and that’s ASSUMING that it actually did fail and was not simply a matter of code(?) present, converter automatically blamed, and it became a done deal.

You don’t understand about getting an independent mechanic / shop to test the exhaust gases with a gas analyser. You have to call around for shop to ask if they have this capability. Even if the dealer says that they can do the checks, I don’t trust them to actually do them, or tell the truth about the results. It’s in the dealer’s vested interest to “find nothing wrong”.

I didn’t really expect a straight answer when I asked the service writer about the cause of the converter “failure”. The car did originally go in for CEL. I didn’t question the diagnosis because I have no foundation. The repair was done, cost was minimal, and the CEL is reset. Now I just need to make sure there is no future problems and I certainly don’t trust the dealer. Thanks

I don’t think I explained myself very well. I don’t intend to let the dealer do any diagnosis, but I will let them do the repair [part replacement], for the balance of the warranty. The independant shop that does the work on our other cars has the necessary equipment. Thanks