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  1. #1
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    Default How do you know if you need a new catalytic converter???

    I know I have a hole in my muffler and plan to get a new muffler next week. But the question came up about whether I also need a catalytic converter and there seems to be different opinions about how you know. The muffler guy says if it's rattling you need a new one and I do hear some rattling from underneath my car. But someone else said if you need a new catalytic converter, your car won't have any power, it will feel like it doesn't want to go. I'm halfway afraid to post this question because I might end up with five more opinions. But maybe I can go with the one I get the most of. LOL!
    Jo Ann






  2. #2
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    Quote Originally Posted by ElizaDoolittle View Post
    I know I have a hole in my muffler and plan to get a new muffler next week. But the question came up about whether I also need a catalytic converter and there seems to be different opinions about how you know. The muffler guy says if it's rattling you need a new one and I do hear some rattling from underneath my car. But someone else said if you need a new catalytic converter, your car won't have any power, it will feel like it doesn't want to go. I'm halfway afraid to post this question because I might end up with five more opinions. But maybe I can go with the one I get the most of. LOL!
    You only need one.

    Is your check engine lite on? If so and the code is P0420, (catalyst efficiency) then you would need one.....if its not on, you dont NEED to replace it...plain and simple.

    If you have a rattle it is going bad and eventually will need replaced once the catalyst material deteriorates enough to plug the exhaust outlet...this could take years to happen....and usually will turn on your check engine lite before it actually plugs up the outlet.

    Cherokee's last so long that you do usually end up replacing the cat...but use the above guidelines before doing so.

    Or...in your case Jo...just call me.
    "I would rather laugh with the sinners than cry with the saints.....the sinners are much more fun". (Billy Joel)


    "The truth is incontrovertible, malice may attack it, ignorance may deride it, but in the end; there it is." (Winston Churchill)








  3. #3
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    Mark! My hero!I knew you'd be there!

    The engine lite came on a couple weeks ago for about an hour and then went off. But it didn't show any kind of code. I thought maybe it was because I drove around on empty for a while. LOL! I think I actually would LIKE to replace it while he's replacing the muffler. It's psychological, I guess. I would hate to put a shiny new muffler on a dirty old cc, you know. I called Meineke and it would be $550 for the muffler and cc. But the Jeep dealership told me about a muffler guy out in the country that they recommend and his price for both is only $320. I was definitely going to get both but then this week my stupid brakes started grinding!!! Grrrr. Where's my rich old man when I need him???

    My cherokee only has 230,000 miles on it. I'm just getting her broke in!!!

    Mark, I think I don't have your number any more.
    Jo Ann






  4. #4
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    Just another word to others out there on this subject...(not you Jo, I KNOW your Jeep doesnt apply)....

    No matter what kind of vehicle you bought on American soil the catalytic convertor is covered by a Federal Emission Warranty for AT LEAST 8 years or 80,000 miles, period...some states are longer (I believe california is 150,000 miles) you engine computer (sometimes called a PCM or ECU) is also covered by the very same Federal warranty....it doesnt matter whether you are the original owner or the 12th owner of the vehicle.
    "I would rather laugh with the sinners than cry with the saints.....the sinners are much more fun". (Billy Joel)


    "The truth is incontrovertible, malice may attack it, ignorance may deride it, but in the end; there it is." (Winston Churchill)








  5. #5
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    What does a catalytic converter do anyway? ....in a nutshell.
    Jo Ann






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    Many vehicles, including one of mine, have more than one catalytic converter. Your "check engine" light does not always come on if it's bad. It's true you will have a definate loss of power if it's bad. Muffler shops etc. can test them.

  7. #7
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    Quote Originally Posted by ElizaDoolittle View Post
    What does a catalytic converter do anyway? ....in a nutshell.
    It's for exhaust emission control, required on all US vehicles for the last 30 or so years, or to keep the air cleaner in other words.

  8. #8
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    See, here's the problem, both of these gentlemen are correct. I have been working for a GM dealership in California, in the service department, for 18years. While I don't "fix" cars, I process all of the warranty claims through GM (and Subaru) and occasionally act as a service advisor (although I hate it).

    NORMALLY, if your catalytic converter goes bad, it will turn on the check engine light (or SES light) but NOT ALWAYS. A code P0420 is the code for a "bad cat"...your muffler can be the source of the rattle or even a loose heat shield or broken weld.

    I've not heard of anyone replacing a cat as "preventative maintenance" but it doesn't seem like yours is very expensive (they can be $1000+ here).

    They help control emissions and you cannot pass a smog if the check engine light is on or if you have a bad cat (but there are only a few states that require emissions testing NJ, Cali, and I think Fl.). So, you can technically drive with a bad cat indefinitely. Cats are covered for 8years/80000 miles even in California (only a few vehicles have ever had extensions or 'special policies' to cover them til 120k miles).

    That's basically the extent of my knowledge...
    Lynn
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  9. #9
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    Emission testing is more related to the city/county that you live in. I can get by without catalytic converters on two of my Porsches, (shhh) but two counties away they are required to test.

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    Usually if your Cat. goes bad it will gradually get worse, causing reduced gas milage, performance, etc. Bottom line, if it's bad it will have to be replaced.

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