clogged catalytic convertor?

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Nov 10, 2005 | 10:38 AM

freshduckie

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From: Michigan

clogged catalytic convertor?

I was told my catalyic convertor is clogged on my 01' ws6 m6 51,000 miles. When you tap it it seems to make a metallic sound, anyhow the car jerks randomly and the performance sometimes seems to not be there. I tried to get the dealer to fix it but they hooked it up on a machine and said "no codes and everything seems fine". So is there any kind of test I can do to it to show that is is a bad cat?

Thanks

Nov 10, 2005 | 04:06 PM

Kirby

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From: Midland, TX

Quote:

Originally Posted by freshduckie

Well...since the cat is made of metal it should make a metallic sound.

If your cat was broken inside, it would rattle when idling and when you bang on the cat. As far as it being clogged...? I would take the pipe off by the 3 bolts at the top and the 2 at the y-pipe. After you take it off, beat the **** of the honeycomb material inside. Gut those bastards!!!

Your car will run better with the slighly less backpressure anyways.

Nov 10, 2005 | 04:26 PM

dschmittie1

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Well the only problem with gutting your cats is you will get an SES light unless you get O2 sims. The dealership wasn't working with you very well. If you said you have a performance problem that could be from a clogged converter that WILL NOT set any trouble codes. The way to check this out would be to unbolt the exhaust before the converter and drive the car open exhaust and see if it runs different. The Dealership can replace this under warrenty for it being clogged and affecting performance(I work in the service department at a dealership and have done this already on a customers car more than once). Plus your converters are covered under a 8 year 80,000 mile warrenty from factory. Hope this helps

Nov 10, 2005 | 04:31 PM

Kirby

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From: Midland, TX

I may even be willing to get rid of my O2 sims since my buddy has HPTuners. I think gutted cats would probably run better. It all depends on how strict your local emissions laws are and if you prefer a louder exhaust. Performance....gut them. Grocery getting....just have dealership fix and leave on car.

Nov 13, 2005 | 12:20 PM

freshduckie

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Is it fairly simply to unbolt and check the convertor out myself? It varys on the performance but it seems to jerk alot right after I get out it a bit. And it does make a noise a idle a bit. I just don't see why it would not throw a code.

Thanks

Nov 13, 2005 | 02:44 PM

RPM WS6

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From: Schiller Park, ILL Member: #317

Quote:

Originally Posted by freshduckie

Is it fairly simply to unbolt and check the convertor out myself?

There are three bolts that hold each cat to each manifold (all years '98-'02). There are two nuts per each side that hold the other end of the cats to the Y-pipe on the '00-'02 cars, on the '98/'99 cars there is no way to unbolt the cat on the passenger side from the Y-pipe end, you have to cut it.

It is likely that after 51,000 miles you will have a hell of a time getting the three manifold-to-cat bolts out without breaking one (or more) of them.

Nov 13, 2005 | 03:08 PM

dschmittie1

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From: York, PA

Getting them off isn't bad if you have a tourche to heat them up with. I have seen if before where a clogged converter will affect performance but it is still operateing as designed and doesn't set a code. It just creates more of a restriction and that isn't going to set a code