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Catalytic Converters

Discussion in 'Performance & Fuel' started by 95C1500, Aug 17, 2013.

  1. BurbanMan

    BurbanMan Member

    All it does is filter the exhaust. There is no additional loss or gain to having one. I feel we're gonna agree to disagree. IMO replacing them is a waste of money if your state doesn't require emissions testing
  2. tbplus10

    tbplus10 Super Moderator Staff Member Platinum Contributor 1000 Posts

    Not to continue arguing you on this point but barometric pressure and altitude most certainly have something to do with the equation, their part of the overall equation along with O2 sensor inputs to determine fuel mix and metering.
    With basic operating systems all that needs to be developed is fuel tables, if you have a basic fuel table it can be modified to develop a custom designed fuel table which when substituted for factory table becomes a custom operating system.
    You dont have to know anything about those 2 trucks, the fact is you made the statement the only way "you knew of" and I was pointing out there are other ways to do the same thing, that with the correct knowledge and tools are just as easy to complet and achieve the desired end result. Just because you may not be able to develop an operating system with previous developed portions coupled together doesnt mean others cant either.
    There are people that understand code and can develop systems relatively quickly with little effort. I personally am not one of them, but I know a few that can.
    Its actually a lot like using an aftermarket tuner, Some aftermatket tuners simply carry pre made lines of code and substitute other lines as you make tweaks to the system to customize how you want the engine to run.
  3. dobey

    dobey Member

    Yes. And the pressure is read on the intake side. The pressure itself has nothing to do with what the O2 sensor will read from the exhaust. They are separate values which feed into the same computer, for it to make adjustments on. As I said, there are many other factors which affect the exhaust gas content.

    A fuel table is not an operating system. It's easy to tweak a fuel table, particularly if you have experience doing it on the same types of vehicles with the same ECMs and the same types of modifications done to them. Writing an operating system is a different feat entirely. I am a professional software engineer, so yes, I do know what I'm talking about here.

    I need to know about those trucks if you're going to use them as some sort of comparison to a statement I made. I never said "the only way I know of." I said the only easy way. There are plenty of ways to do plenty of things, but they aren't all easy. I know and understand "code" and can develop many things relatively quickly with little effort. I never said other people can't also do that. I said nobody can build an entire operating system for an unknown specification of hardware, in under an hour. And that's exactly what you were claiming was done. It's also not easy for any random person to do it. Nor is it cheap for those random people to pay someone else to do it.

    The "tuners" that you're referring to here (the boxes that plug into the OBD port and have an LCD screen and a few buttons), don't change the operating system or "have a few lines of code" they insert. What they do, is have various fuel tables and other maps, stored in a small amount of memory, sometimes multiple different versions of them, and they allow you to simply flash those different values, into the factory ECM.

    You made several assumptions about what might have been done to the truck, because you have done something wildly different than what most people do, when removing the cat from their vehicles. The assumptions didn't do anything to actually help answer the questions being asked. Rather than making assumptions, it is better to ask direct questions to determine what has actually been done, and what any existing problems are. And it's better to state specific answers to the questions being asked, rather than to recite opinion or rhetoric based on politics and anecdote.

    - - - Updated - - -

    Whether testing is required or not, is irrelevant. Federal law requires them, and most state and local laws also require them to be present, as part of noise reduction system. They don't simply filter the exhaust, either.

    Your comment was still totally useless and not at all helpful to any conversation in this thread. Yes, you are free to your opinion, even if it's wrong. There's a reason it's called opinion, and not fact.
  4. tbplus10

    tbplus10 Super Moderator Staff Member Platinum Contributor 1000 Posts

    I never said pressure and altitude was read on the exhaust side, I said it was read and was an input needed, you said altitude didnt matter, altitude directly affects pressure. Yes what goes in the front affects whats read out the back.

    A fuel table in this particular instance is a part of the operatiing system and affects how the system will operate after its been substituted for an existing fuel table.

    The reference to my trucks was an example that it can be done despite your insistance it cant. Or as you say "easy way". Yes some people can tweak computers to achieve results while others prefer modifying hard parts.

    Arent fuel tables in digital form considered lines of code when broken down and developed?
    And when inserted they do change the system, it now operates differently when their inserted, that would be a change to the system whether permanent or temporary.

    And despite your feelings this truck should operate with a cat convertor on it again the truck is operated in Kuwait, thats not part of the US and and doesnt fall under federal law, federal law only applies to the US, period. And Kuwait doesnt have noise restrictions either.

    Again what may be hard for you to accomplish might not be hard for others. Theres many good programers that are fully capable of doing things others cant.

    And yes your free to your opinion too, even if its wrong.
  5. dobey

    dobey Member

    Please stop twisting things around to fit your world view. That is not what I said at all. I said altitude and air pressure is irrelevant to the discussion. It's obviously relevant to the ECM or there wouldn't be MAF or MAP sensors on the engine. But altitude and ambient pressure do not directly affect the O2 sensor readings. Only the exhaust gas itself does.

    Fuel tables are not lines of code, no. They are simply values, in the same way that the names, addresses and phone numbers you write in an address book are values, and not lines of code. There are no "lines of code" directly in the ECM, either. The "operating system" or "program" that resides in the ECM, is simply a bunch of 1s and 0s arranged in particular order after the original code had been compiled down to "machine code," that is specific to the CPU or MCU in the ECM.

    Changing the values in the fuel tables no more changes the system operation, than storing a bookmark to a web page on your computer would change how your computer operates. The system is designed and written exactly for that purpose.

    As for the truck being in Kuwait, vs fedral or noise laws, go back and look at what I was replying to when I mentioned the federal and noise laws. The Kuwaiti laws may or may not be similar. Making an assumption as to whether they are or aren't, doesn't help. It may be in the most unstable part of the world, but it is still a sovereignty, with its own laws. Also, [MENTION=62001]atish_therock[/MENTION] is US Military, and the truck is stored/driven on a US Military base, then it actually does need to comply with US Federal law, as it is on US soil. So please don't state outright "Kuwait doesn't have ____ laws," as fact, when you clearly do not know.

    What is a fact is that [MENTION=62001]atish_therock[/MENTION] clearly stated he preferred to have the lower emissions, and that he asked what may be affected, if the cat is removed. What I did was answer that exactly, and recommend the reinstall of the missing equipment, to bring it back to factory specs and reduce the emissions. That is exactly what was asked. I did not make assumptions about what I had previously had done to my vehicles, or my political opinions of the equipment in question, or based on where the truck is located. Because all those assumptions are not relevant, and do not answer the questions that were asked.

    And again, you are talking about some things you don't understand, and assuming that they are easier than they are, because you've misunderstood what was done to your truck. Your ECMs operating system was not replaced with a "home made" one. It had the fuel and timing tables altered, and perhaps may have had existing and unused functions re-purposed to trigger water/meth injection systems, or such. That is simple ECM tuning, and is a far cry from writing and replacing an entire operating system on an arbitrary ECM. Yes, those tweaks could be done, and reasonably tested in under an hour. Writing and replacing an operating system though, cannot. I have been programming computers for over 20 years, and work with some of the best software engineers in the world. Operating systems that work right, on arbitrary hardware, are not simple. It's not bad that you misunderstood what was done, though. Such misunderstandings happen all the time with me, as people who don't really know what I do, will assume something is easier or somewhat different, than what I might have done, simply because I am very good at what I do, and they don't understand. Hopefully, this explanation will help you understand what was done, better, though.

    And luckily, I haven't stated any of my opinions yet, only facts, so therefore I am not wrong, even if you managed to conflate my reply to your previous post, and my reply to Burbanman about the legality of cat removal and the uselessness of his comment, because the site combined them into a single post with only a low contrast "--- Updated ---" to separate them.

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