| Homms'03Murano |
Hi Ya'll. what is a Thre Way Catalyst, Where is it located, What is it's JOB.......and for goodnesss' sake what's the difference between the
THREE WAY CATALYST and CATALYTIC CONVERTER?
Also:
a- Any DIY or Tips?
b- if bad/damaged or etc...can it be repaired?
c- if no and must be replaced, is it a common part that a non-OEM
can be used?
d- HOW MUCH?
All I know (which is not much) is that it's connected to the exhaust system and is related to performance, somehow.
As usual, any info is seriously wecomed.
O.B.T.W (oh by the way), r'nt i due for a promotion from junior memeber to the next level, c'mon....!!!! |
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| njjoe |
H-
When talking about your MO, the terms "three-way catalyst" and "catalytic converter" are interchangeable. Your MO has three catalytic converters; all three are three-way catalysts.
One each is located just aft of the exhaust manifold, and the third is located between the "Y-pipe" and the muffler.
They are called three-way catalysts because they are designed to work on three different compounds in the exhaust stream:
1) Converts Carbon Monoxide to Carbon Dioxide
2) Converts Nitrogen Oxide to Nitrogen and Oxygen
3) Converts unburnt hydocarbons (gasoline and oil) to Carbon Dioxide and Water
In other words, the three-way catalysts on your MO take the pollutants in the exhaust stream and convert them to relatively harmless gases and water vapor.
The catalytic converters require no maintenance and cannot be repaired. They must be replaced if they fail.
Most big-name muffler shops and auto parts stores carry aftermarket units for the MO's rear converter, however I am not sure if non-OEM units are available for the front two.
The MSRP for the front converters is $759(US) and the rear goes for $726(US). Aftermarket units can be had for less than half the OEM cost.
I hope I was able to answer your questions. If not, let me know and I will take another swing at it.
-njjoe |
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| Homms'03Murano |
Njjoe you hit that one outta the freekin' park. No need to take another swing at it. Thanks a lot for your carefull & elaborate explanation....u really had "dummies" in mind when you explained, hehe.
Guess I'll have to shop for one over here (nigeria) which is going to be hard. OBTW, if I cant get the Cat here is it still ok to drive the MO like that?....no affect at all to the Car?....just curious.
H- |
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| njjoe |
h-
Catalytic converters can fail in one of two ways.
1) The substrate (the material inside the converters) can become coated with a contaminant that prevents the exhaust stream from coming in contact with it.
2) The converter can overheat causing the substrate to melt.
The first way is usually caused by using leaded gas or introducing antifreeze into the exhaust stream from a head gasket leak.
The second way is usually caused by running an overly-rich fuel mixture for an extended period of time.
If your converter failed due to #1, then it will not harm your engine. However, if it failed due to overheating then the melted substrate can restrict the exhaust path and cause your engine to overheat. There have also been a few reports of the substrate being drawn in to the engine causing mechanical damage.
What do you suspect caused your cat(s) to fail?
-njjoe |
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| Homms'03Murano |
Njjoe, I think it's the first. Over here we don't have grades of Petrol to choose from but the petrol is OK for the most part. however i occaisionaly use Fuel treatment fluid & Fuel injector cleaners (I'd say once a month of both). The substrate or I think the catalyst (isn't t) found inside the converter is torn up (they look like tiny soft metal-like sheets). I know this cause my man shook the CAT and crumbs fell out.
Well, after doing a bit of research on the web, I found out that its not damaging driving the car in this condition but a replacement would be in order. Does this help answer your question?...
Thanks for your feedback.
appreciate. |
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| Trbayth |
(Wondering)...
Being in Nigeria does he even legally need the cats?
Trb |
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| Eric L. |
quote:
Originally posted by Trbayth
(Wondering)...
Being in Nigeria does he even legally need the cats?
Trb
It could theoretically affect drivability as the O2 sensors detect both pre and post-cat emissions and adjusts the engine accordingly. Running with a bad cat or no cat would definitely affect performance. |
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| Hilbe |
quote:
Originally posted by Eric L.
It could theoretically affect drivability as the O2 sensors detect both pre and post-cat emissions and adjusts the engine accordingly. Running with a bad cat or no cat would definitely affect performance.
I have no cat on my Maxima Y-Pipe. It actually makes the exhaust flow a lot better without it. More horses at the wheels.
There are the other 2 cats on the headers, so I'm not worried about my emissions. Most people that take them off the Nissan family of vehicles still pass emissions testing without the Y-Pipe catalytic converter. |
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| njjoe |
quote:
Originally posted by Eric L.
It could theoretically affect drivability as the O2 sensors detect both pre and post-cat emissions and adjusts the engine accordingly. Running with a bad cat or no cat would definitely affect performance.
E-
That's not necessarily true. Since there is no sensor aft of the third cat the engine management system has no way of telling if the cat is operational or missing. As evidenced in Hilbe's case, you can remove the third cat and it will not adversely affect performance.
However, removing either of the two manifold-mounted pre-cats would cause problems with the engine management system.
-njjoe |
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| biggun |
| Not sure if this is the case in Nigeria, but I think there is a law in the US that requires manufacturers to provide a 5 year warrantee on CATs. |
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| njjoe |
quote:
Originally posted by biggun
Not sure if this is the case in Nigeria, but I think there is a law in the US that requires manufacturers to provide a 5 year warrantee on CATs.
bg-
You are correct, unfortunately that is not the case in Nigeria.
According to information gleaned from the 'Net, Nigeria eliminated lead in it's gasoline only 4 years ago and has no formal regulations in place regarding pollution control for cars.
-njjoe |
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| biggun |
quote:
Originally posted by njjoe
bg-
You are correct, unfortunately that is not the case in Nigeria.
According to information gleaned from the 'Net, Nigeria eliminated lead in it's gasoline only 4 years ago and has no formal regulations in place regarding pollution control for cars.
-njjoe
Ah, that's too bad. That would lead to believe that the use of lead in their gas was the problem, but then I re-read Homm's posts and recalled that he uses fuel substitutes/cleaner on a regular basis.
I remember looking to buy a fuel substitute or cleaner and reading on the bottle that it may cause harm to the CAT. Heating it up would make sense, which is why I don't use them, period. |
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| Hilbe |
quote:
Originally posted by njjoe
E-
That's not necessarily true. Since there is no sensor aft of the third cat the engine management system has no way of telling if the cat is operational or missing. As evidenced in Hilbe's case, you can remove the third cat and it will not adversely affect performance.
However, removing either of the two manifold-mounted pre-cats would cause problems with the engine management system.
-njjoe
Wow, you agreed with me ;)
Yes, the Altima and Maxima guys usually get a Check Engine Light if they put headers on the vehicle (remove the cats).
I personally think if you don't want to spend a lot of money you should just take it to an exhaust shop and replace the cat with a straight pipe. |
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