Catalytic Converter Puzzle

[madmanmapper]

Hi guys! Welp, my exhaust pipe disintegrated and fell off right in the middle of my car. Plus I had known my cat was clogged up before that anyway. Now my LeBaron is really noisy, but it sounds cool . Anyway. I live in Illinois, so emissions tests are no concern for me! I want to get rid of my catalytic converter. It's choking my poor little Mitsubishi 3 liter. Not to mention Chrysler's EEK's exhaust flaws (the pipe gets smaller towards the back). I don't think I can afford a whole new exhaust, if only pipe and a muffler. But for now, I want a straight open pipe until the middle of my car but hooked up to the rest of the old exhaust via a flange. lol then I can have a totally open pipe whenever I want. Just like my friend Jeremy had done to his Olds wagon. So anyway. I obviously have only one heated oxygen sensor before the cat. By removing the cat, I'm afraid I may confuse my LeBaron. How bad for the computer (and thus my engine) would it be to replace my cat with a piece of open pipe? I would like my LeBaron to think that it still has a cat, obviously because I want it operating properly.

Any advice? Thanks!

[Airjer_]

Just because you don't have emissions testing does not mean your exempt from fedral emissions standards. You are required to have a operational emissions system as intended for the year of the vehicle. Giving advice on disabling/removing/modifing this sytem would be in bad judgement and unethical. You might be on the honor system but you are still required to meet those standards!!

If you play your cards right you can find rebates for exhaust and the cats are valuable if you find a recycler to buy it from you. Its all nuts and bolts so you can do the install yourself and save a bit of cash!

[madmanmapper]

My car is a *1972* Chrysler Lebaron that just so happens to have an oxygen sensor, computer system, and catalytic converter, which are *NOT* required for this model year. Now can I please get an answer to my question?


BTW it's not all nuts and bolts fool, you need a welding machine to do such jobs.

[Scrapper]

if and i mean if your cats are ok you can nock the middle out of them and leave cat or cats on there. another thing if i said if you know a guy does exsaut work if cats are no good hook it up without.LOL remember this guy is giving you a hard time..that's the only think i don't like about this forum it people want to argue and say shit like that air jerk or what ever his name is. dis regard what i just told you to do sorry.

GOOD LUCK....

SCRAPPER1

[madmanmapper]

Ah thank you for a reasonably helpful response! Yes I know what you mean... I pretty much hate all forums for such things, except for one, just one, that no longer exists .

And yes, I could just hollow out my cat, if that's what you mean. That's the old school/ghetto way . Wait, what do you mean disregard what you told me to do? I guess I am anyway lol. But yea, I was going to go to a muffler shop I know. They don't mind doing open pipes. At the very least I need to weld the pipe back together as it has simply rusted in half. I want new pipe anyway. And I don't want to be one of those fools who just saws off their whole exhaust system and says "Listen to that baby rumble!" when in reality it just sounds like a big lawn mower and smells as bad. I want to do it the smart way. But I don't know what the smart way is. I want my car to think that it's normal. So I'm concerned with the computer implications of running with no catalytic converter.

In a nut shell: I want to have no catalytic converter with one muffler on the end, I can have that done no problem. But I also want a way to convince my computer that nothing is wrong.

Besides, the cold hard fact is that catalytic converters make cars burn more gas. It's a fact!

BTW Airjer, that was NOT "quality automotive advice." False advertising!!!

[Airjer_]

I suggest checking the federal law regarding emissions standards. Once you know what you are talking about then you are welcome to criticize my comments. Your question already wreaks with automotive ignorance so its no surprise than you would be defensive and agitated at my response!

Wasn't the first model year Lebaron 1977? I couldn't even find a '72 in the books. Must be a real rare and special car and since there isn't anything in the books than I guess your right. If the car doesn't exist than it doesn't have to meet any emissions requirements. I apologize!

__________________________________________________ __________________________________________________ ____________

I realize you think you're right, but I know I am right!

[madmanmapper]

I'm automotive-ly ignorant? I can't believe you even bothered looking. Who's ignorant now? And why are you so insistent upon blind obedience of emissions laws? What if my car is a 72, before emissions laws applied? What if I'm using and EEK powertrain for an off-road vehicle? What if my car really doesn't exist and I'm simply posting a question here to get a theoretical answer? It would be nice to get a helpful response instead of a post saying "I'm right and you're wrong," since I have not provided an answer to my own question, I cannot be wrong. And actually you have not provided an answer either and thus you cannot be right. So please answer my question or stop replying.

[Airjer_]

An O2 sensor is nothing more than a battery. It creates an electrical current based on the difference in oxygen levels in the exhaust versus the oxygen levels on outside of the exhaust. Less oxygen in the exhaust = more current = rich. More oxygen in the exhaust = less current = lean. The O2 does not care what is in front of it or behind it. All it does is measure the difference in oxygen!

From the 1990 Amendments to the clean air act, established in 1970.

Another change involves tampering and misfueling. Such activities have always been discouraged, but were previously illegal only for commercial operations. “Backyard mechanics” now are also subject to stiff penalties for deliberate tampering.

You see when somebody posts about tampering with a cat it can pose some serious dilemmas. For one its illegal! Its never a good idea to give advice for a potentially illegal activity, especially in a public forum!! We don't know if its for "off-road" or if you incorrectly typed in the year. All we know is that you stated it has an O2 and a cat that you want to remove!

[madmanmapper]

Exactly, and that's all you need to know.

Anyway, it seems my cat was not clogged up at all so I'm keeping it until it becomes clogged or rusts away. Still, it's good to know the theories about such things.

And this is a car forum, we discuss cars here... not laws. Besides, if you don't want to answer my questions, you could simply have not posted, instead of saying that I am essentially just wrong to ask such a question. You basically insulted me for wondering how emission systems work. And was it really THAT hard to just answer my question?

Whatever, I had my pipe welded back together, it's so quiet now.

O2 sensors measure the amount of oxygen, as you have just stated. Now, everyone knows catalytic converters create some "back-pressure" or basically restrict the flow of exhaust gases. Thus, if the flow is restricted, there is going to be higher pressure, or more dense, exhaust gasses between the engine and the converter, which is where the O2 sensor is. Thus the car's computer is tuned to read the amount of oxygen in the exhaust gas while under this pressure. With no converter, the pressure in the area of the O2 sensor will be lessened, thus the exhaust gas will be less dense than it should be. Less density of the gas means less oxygen will be in it. So you say less oxygen will be interpreted as running rich, thus the computer will adjust to run leaner. This leaves 2 possible results that I can think of:
- The difference in pressure with a converter and without it is negligible.
- An engine would need to run slightly richer in order to make up for the power lost by the back pressure created by the converter, thus without it, it could run slightly leaner and still have the same power as with a converter, but run more efficiently.

Is there a third possibility?

[Airjer_]

I never insulted you in my original post. I did make you aware that tampering with emissions is illegal. I'm sorry that educating you on this fact came across as insulting, which if you reread the post I never insulted anybody!

In fact the first insult is when you called me a "fool"!

The difference in back pressure with or without a cat in place will hardly have an influence on what the O2 is reading if any. The back pressure a cat creates is a minimal part of the back pressure the entire exhaust system creates which is pretty minimal itself (if I remember right normal back pressure is around 1/2 psi). It doesn't care about how fast the exhaust is coming at it all it wants to know is the difference in oxygen.

[madmanmapper]

Apologies, I meant to say that I perceived your post as an insult to my intelligence. Not like I didn't know it is illegal. Doy. What I don't understand is why you consider it a mortal sin to run a car with no cat.

And so basically the difference in back pressure is negligible, exactly what I wanted to know!

[Airjer_]

There are certain requirements that need to be in place in order for a car to be legally on the road. If we abuse the priviledge of letting us be able to take care of those requirements on our own than sooner or later the state or government will make those decisions for us (California is a perfect example and don't forget all the states the require "safety" inspections). That doesn't come free. Higher taxes and licensing fees will cover the extra expensses the state will have to do these inspections!

We don't get to pick and choose the requirements that we are going to meet. If we are resposible enough to drive than we should be responsible enough to keep our vehicles in good working order and at least meet the minimum requirements that have been set to have the vehicle on the road.

As far as emission are concerned, If they have been altered or tampered with than the vehicle is no longer eligiable for on road use and cannot be sold for on road use. It is one of the minimum requirements that needs to be met for the vehicle to be on the road just like a car doesn't belong on the road with a bald tire(s), exterior lights that don't work, or expired tabs.

[Scrapper]

still stuck on law and he keeps going..lol..see this is crazy.. i think jesse james could put 10 on there and you would still bitch..out of this one.