I was under my truck today while changing the oil,and noticed that my pickup has what looks to be two catalytic convertors. Was this part of some emissions package? Do I really need two of them?

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Nick

1987 Dodge D-100(225/904) Daily Driver
1979 Dodge Ramcharger (318/727/NP208)(Under Construction)

Yup. My 80 Volare had 2, also. 80s rear drive V8 Mopars had 3.... YIKES!!!

If you are exempt from emissions testing/inspection, throw them in the trash where they should be.

My Fifth Avenue has three cataclysmic convertors. No wonder why my exhaust smells horrible. They are destined for a date with the sawzall very soon.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

I'm planning a 2 1/4" exhaust eventually,and I still need it to pass emissions,would I be ok with just one cat.?

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Nick

1987 Dodge D-100(225/904) Daily Driver
1979 Dodge Ramcharger (318/727/NP208)(Under Construction)

If all that you are subject to is a visual inspection just gut the convertors and put the empty shells back on.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

In IL we have the sniffer test and the gas cap test,no visual.

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Nick

1987 Dodge D-100(225/904) Daily Driver
1979 Dodge Ramcharger (318/727/NP208)(Under Construction)

How about one large high flow catalytic convertor utilizing air injection?

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

The converter(s) are there for a good reason. Certainly there are improvements that can be made in the selection and placement of the converter(s) to optimize exhaust flow while minimizing emissions, but just chucking them in the trash is irresponsible, unhelpful, and just generally not a good idea.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

...and without the catalytic converter, you'll usually flunk the sniffer test (which is a good thing. You should flunk the test with a dead or missing converter!)

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

A "high flow" converter isn't what you want if you're trying to replace a 2- or 3-converter system with a single converter. Those "high flow" units don't do as good a job of cleaning up the exhaust as regular converters, which if you buy a quality brand and pick a correctly-sized unit, present essentially zero exhaust restriction.

You can sometimes get away with one converter in place of the original two or three, depending on which converter you pick, where you locate it in the system (as far forward as possible) and the emission test standards in your area.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

There are no locations where there is only a visual inspection—there is always a sniffer test of some variety. Gutting the converters is just as poor an idea as throwing them in the trash altogether.

Here's another thing to think about: If you are in one of the very few areas left that don't have emission tests, how long do you think you're going to keep not having emission tests if you go making your late-'80s cars as dirty as mid-'60s cars? For that matter, how long do you suppose you're going to get to keep your pre-fuel-injection cars if you go reinforcing the ignorant notion that old cars are necessarily filthy gross polluters? Your "throw it in the trash can! Gut it and leave just the shell!" idea plays right into the hands of those who would like to legislate old cars off the roads.

Do you litter just 'cause you're not on an Interstate highway where the fine is $1000? Do you steal just 'cause nobody's watching you and you're sure you won't get caught? Well, this is the same deal: Just 'cause there's no lawbook hanging over your head saying "What you want to do is illegal", doesn't mean it's OK to do what you want to do. Please give a thought to the people around you, who have to breathe what comes out of your car's tailpipe.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Newer type converters don't restrict exhaust flow like the older pellet type converters.

If the 2 converter systems have an air pump to the second converter, you can replace them with a converter that has an air inlet to the middle of the converter.

The first converter (or first half on newer converters) will reduce NOx
the second convertor (or second half) with the addition of air will take care of the CO and HC's.

In some cases 2 converters are used so the the first one lights of faster (i.e. heats up faster due to being closer to engine). It may not be able to handle the full exhaust load due to size/space constraints, thus the need for the second converter farther down the line. But it does help reduce emissions on a cold startup and thus it's use.

Converters should be placed as close as possible to the exhaust manifold so they heat up rapidly and can do there job. As newer converters are smaller than the old type, you may get away with just the 1 in this case too as the 1 converter can be placed in the first converters location.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

While this subject is going, is there a converter you can buy that will still work w/o needing an air pump? I'll be replacing mine eventually, and if I can (in good conscience) ditch the air pump at the same time, that would be great.

You can add a home-made passive air pump.

With a converter that has an air line input to the middle of the converter, put a exhaust check valve on that air line input.

With the exhaust pulses, there's a low pressure between pulses, and it will suck air into the converter.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

It's usually a 3-way converter, that can be used as a 2-way converter by leaving the plug on the air line intake in the middle.

Works as a 2-way converter until you pipe in the air.


Note: 3-way is HC, CO & NOx; 2-way is HC & CO

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes