What catalytic converter is on a 98 GMC?

Discussion in 'Shop Talk' started by hisenthlay, May 17, 2006.

  1. hisenthlay

    hisenthlay a.k.a. hyzenthlay

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    Does anyone how I can tell what kind of catalytic converter is on my 98 GMC Sierra 1500? Meaning monolithic, pelletized, etc.? I know approximately nothing about auto repair. The truck is a 4x4, 5.0L V8, gas engine....

    I just bought this truck last week, and before I got it, I had it checked out by a mechanic (at Midas) who said that the catalytic converter was broken because it rattled. (Don't worry--I got a dicount on the price to fix it). But I was just reading about this online, and I've seen articles that say if a pelletized converter DOESN'T rattle, then it's broken, but a monolithic converter is broken if it DOES rattle. I also saw that you can do emissions tests to find out for sure, but I don't know if this guy did that. I'm just a little nervous about him using rattling to diagnose the problem, before I shell out hundreds of bucks. I did a google search to try to find out what kind of converter I have, but came up with zilch.

    Also, the guy at Midas said it would be $200, and I just talked to a more local mechanic, and he said it would be $379 plus $68 for labor. Do either of those prices sound fishy to you? I'd just go back to Midas, but it's about 1.5 hours away, and the other guy is 5 minutes away and has a good reputation.

    Thanks!
     
  2. rambler

    rambler Well-Known Member Supporter

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    In general, you get better milage with a hollow cat. That might be illegal tho, some locations check for this, some don't never check.

    Emissions vs fuel milage. I'm not always sure we are always on the right course in that debate.

    Just babbling, I'm not really helping you.

    --->Paul
     

  3. clovis

    clovis Well-Known Member

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    Why do you need to have the cat replaced???
    Do you have inspections in your state?
    Clove
     
  4. Red Devil TN

    Red Devil TN Well-Known Member

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    It is likely a monolithic cat. Just because it is rattling doesn't mean it's toast -yet. The core likely broke free. How long will it last? That's a gamble. Now the other question of course is whether the heat shield is rattling or if it was the core itself.

    IF I got the truck info right, a new, direct fit, maremont part #652046 is about $207 the universal maremont #38765 is about $82. Those are 'local' prices from autozone online. You can probably do better.

    This (if it works) is the search screen for summitracing http://store.summitracing.com/egnse...94924677+4294923429+4294838974+115+4294840138
    Catco direct fit (according to the pic including the y pipe) ~$219. Catco cats are typically a bit better flowing than stock.
    Magnaflow universal is ~$64.

    The other item to consider is the age of the truck. If (after some research) you still fall under the 8 yr/ 80,000 mile Federal warranty on the converter, you may be able to bring it to the dealer and have it replaced.

    The links are at the bottom of this page:
    http://www.discoweb.org/warranty.htm

    That said, I stil don't understand why people are soooo against cats.
     
  5. hisenthlay

    hisenthlay a.k.a. hyzenthlay

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    Thanks!
    Clovis, there are inspections in my state, but the mechanics said I also need to get it replaced because some of those broken ceramic bits could find their way into other parts of my system and cause problems. Besides, I don't mind shelling out a few bucks to protect the environment--I just don't want to pay more than necessary for a new one. That's also why I wouldn't just want to try to hollow it out, like Paul said.

    Red Devil, you answered my other question, too, which is whether there would be any problem with putting a universal cat in there. And the one you found is cheaper, too--the one I was looking at was Eastern brand, and was $93. It also said that it wasn't suitable for Califonia emissions--I'm not exactly sure what that means, but the customer help service of the website selling the cat told me that there should be a sticker under my hood that said something about California emissions. I looked yesterday and couldn't find one. But the cat you found for $64 doesn't seem to say anything about California emissions, so I figure that one should be fine.

    I'm not under warranty for this--the truck is a 98 at 112k miles. But it sounds like it's not going to be as expensive as I feared, if I can buy a universal cat and have them install it.

    Thanks!