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Anyone Added a Catalytic Converter to 71-74 Dodge Charger?

Have always had trouble getting my 95 Dakota to pass emissions because nox numbers was high. The higher no pass numbers didn't start happening until it was about 5 years old and a new converter didn't help but what did help was going in with a cooler engine (lower T-stat) and no air filter (did a good bit of research on what causes high nox back then). Yes, the air filter element raised NOX numbers and driving two miles to the inspection station helped keeping the engine cooler. Hot engines generate higher nox numbers. One time they let it warm up more but it still passed but barely. Doing maintenance to the EGR helped but not that much. Now that it's 25+ years old I don't have to worry about that crap anymore!

FYI.....NOx, which is composed of Nitric Oxide (N20) and Nitrogen Dioxide (NO2), both come from the nitrogen component of air (roughly 78%-79%), with the bulk of the mix being oxygen (O2), roughly 19% andvtge balance is everything else. Sometimes nitrogen is introduced as fuel bound nitrogen (where a nitrogen bearing compound is a component of the fuel). I have heard that Shell has a nitrogen compound blended in tge fuel to "add a cleaning detergent".
From Shells web site: The Shell Nitrogen Enriched Cleaning System uses a patented molecule, which cleans and protects intake valves and fuel injectors. Enriching the molecule with nitrogen makes it more thermally stable and therefore more effective in tough engine conditions with higher temperatures and increased pressures.
Additionally, It might seem like adding nitrogen to gasoline is all the rage among oil companies today, but the idea has been around for years. The U.S. Environmental Protection Agency (EPA) requires that automotive fuels sold in the U.S. contain detergents to help scrub away pollution before it goes out the vehicle’s tailpipe. Some manufacturers have found that adding nitrogen to the detergent helps keep an engine cleaner by reducing the carbon build-up in the gas tank that can in turn “gunk” up the engine and lower performance.
To continue, The nitrogen itself also has a direct cleaning effect, breaking down carbon deposits that can harden on an engine’s moving parts. “If too much collects, this gunk can negatively affect engine performance, causing your car to burn more oil, overheat and burn gasoline less efficiently,” reports John Fuller on the How Stuff Works website. Valves inside an engine are designed to let in a specific amount of air and fuel, he adds; when that process is slowed by carbon build-up, a car won’t perform up to its potential.
But while nitrogen-enriched gasoline may provide a slight bump in engine performance, some worry about adding to cars’ already substantial pollution load, especially nitrogen oxide (NOx), which contributes to smog, acid rain and other environmental problems. André L. Boehman, a Penn State University engineering and fuel science professor, says that the addition of more nitrogen to the fuel mix “generally will increase NOx emissions.” Boehman would like to see more research done so we can know for sure if and how much additional NOx pollution is caused by the use of nitrogen-enriched gasoline.
For its part, Shell Oil, which last spring launched its own form of nitrogen-enriched gasoline now for sale at all of its U.S. filling stations (it is mixed into all three grades of gasoline the company sells), denies that the additional nitrogen has any substantive impact on pollution levels. “Most nitrogen in vehicular NOx emissions does not come from gasoline,” the company told The New York Times. “The nitrogen is primarily from the incoming air that mixes with gasoline inside an engine. NOx is produced when the nitrogen from the air reacts with oxygen under high engine temperature and pressure conditions.”
Professor Boehman concedes that “the detergent additive may have such beneficial effects on engine operation, fuel system performance and other related features of engine system operation that they outweigh the adverse effect” of increased NOx emissions. “For instance, if improved detergency helps to increase fuel efficiency so that you burn less fuel, you may slightly increase the NOx emissions rate per gram of fuel burned, but end up with lower NOx because you burned fewer grams of fuel.”
That said, it is probably a good idea to avoid putting nitrogen in your fuel unless you’re sure the gains will outweigh the detriments. And until researchers know more, drivers might focus instead on minimizing their own vehicles’ overall gasoline consumption and fuel efficiency—and on substituting other cleaner forms of transportation (walking, biking, mass transit) whenever possible.

CONTACTS: EPA Fuels and Fuel Additives, www.epa.gov/OMS/fuels.htm; How Stuff Works, www.howstuffworks.com; Shell, www.shell.us

All you didn't want to know about fuel bound nitrogen and internal combustion engines and NOx formation. BUT, if you're a racer, nitrogen dioxide (NO2) is added to the intake fuel charge along with more gasoline to generate more power during combustion, as the NO2 breaks down yielding O2, to burn the extra fuel added, producing more power, similarly to the old oxy-acetylene cutting torch operation....much higher temps.
BOB RENTON
 
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@RJRENTON I thought all that was leading up to tell me a new coverter should have lowered the NOx lol
 
I was just being silly since it looked like he had copy-n-pasted a novel.
 
Short answer...yes you can add a converter and have it work. You'll be using a two way converter like in the 70's since you don't have computer controlled fuel or oxygen sensors.

However, you shouldn't be getting fumes in your car anyway. Make sure your exhaust is tight and keep the engine properly tuned and you won't have problems with your kids health.

News to me all ever saw starting 75' Mopars were computer-controlled cars, we had one limited production 400 cu. Cordoba that didn't use converters. But something needs to manage the amount of exhaust/fuel going into that converter otherwise it will overheat and damage the car and not last long.
 
I have 74 Dodge Charger with a killer 440 engine, I want to reduce the emissions. I have young kids and I want to take them for a ride without worrying I am exposing them to toxic fumes. Should add a Catalytic converter? I am not worried about loosing power as I already have WAY TOO Much. I found this one from the UK costs around $260 to get to me with shipping:

https://jetex.co.uk/classic-car-converters/

Any thoughts?
Friend I want to help,
Seriously go buy a can of Copenhagen and put a big dip in, next light a cigar and start smoking. As soon as you start feeling dizzy chase all that with a shot of whisky. Next go find the person who stole your balls and take them back.
 
News to me all ever saw starting 75' Mopars were computer-controlled cars, we had one limited production 400 cu. Cordoba that didn't use converters. But something needs to manage the amount of exhaust/fuel going into that converter otherwise it will overheat and damage the car and not last long.
The computers of the mid 70's didn't do a whole heck of a lot except to cause grief! A lot of them actually did cause the cat to overheat and the engines ran bad right off the dealer lot.
 
News to me all ever saw starting 75' Mopars were computer-controlled cars, we had one limited production 400 cu. Cordoba that didn't use converters. But something needs to manage the amount of exhaust/fuel going into that converter otherwise it will overheat and damage the car and not last long.
My brother had a 75 and I had a 77.
Neither had any computer controls just electronic ignition and a carbeurator.
I did put a "test pipe" on mine and tested it for about 6 years.
 
JFC! how did we get here? just put a plastic bag over everyone's head and call it a day :fool:
 
My brother had a 75 and I had a 77.
Neither had any computer controls just electronic ignition and a carbeurator.
I did put a "test pipe" on mine and tested it for about 6 years.

Does the catalytic converter quiet the exhaust much?
Some like it loud! And some don't... like the neighbors.
 
I think the time and money here would be better spent on a EFI conversion. You will always run stoichiometric and fumes will be almost eliminated.
 
Also, keep in mind if the converter can't be efficient in catalyst action you will end up with a rotten egg smell.
 
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