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gutting the catalytic converter?

Discussion in 'Modifications and Projects' started by GForce, Dec 19, 2007.

  1. I have a 05 zx6r and is pretty stock and was wondering if anyone has done this to their bike? Gutting it would make the abit noiser and prehaps making it run richer or leaner but the goal here is to get a few more hp. A PC111 would be needed to make the bike run smoother.

  2. if you're going to mod, do it properly, and legally

    applies to bikes, cars, whatever

    they don't put cat converters on vehicles just to 'slow them down'
  3. I don't believe bikes are required to be fitted under current ADR.

    Most Jap bikes if fitted are fitted so as to comply in countries where they are required to meet strict emission regs, and it's easier to produce one model with one exhaust type, instead of different ones for multiple markets.

    However without wasting my time going through the whole rule, I can't be sure that there isn't a provision that would make removing a cat that was factory fitted (despite the fact it's not a requirement to comply) unlawful.
  4. i was taking more of the hippy/byron bay don't wreck the planet type approach on this one

    find better ways to mod it keeping the emissions clean as you can i reckon
  5. Don't listen to the hippy :p , do it, I will be doing mine in the new year also.
  6. Do it!

    I just put my exhaust on today and its freakn magic, do it!
  7. True, but there's a large number of engines out there running on unleaded without any catalytic converter whatsoever - not to mention the fact that a cat is supposed to be replaced periodically and there's plenty of unleaded cars that are well past that point. Shouldn't really make any difference to noise unless the cat was part of the muffler, neither should it affect running unless the original was particularly restrictive. But fairly sure it's illegal.
  8. I knocked the cat out of my bike a few months ago. It is a little louder but I have not noticed a power gain. It was a new style metalic version so was difficult to remove. I used a square shank screw driver in a hammer drill to get it out and it took ages to do.
  9. hey oz650r,

    did the bike run ok after you knocked it out? eg. it doesnt bog or cause the bike to run crap?
  10. Guess he should run it on LPG/CNG then?
    Or better still don't ride it.
  11. It runs fine with no problems at all. I have also disconected my o2 sensor to smooth out the throttle.
  12. ^^If a mechanic does "gut a Cat" its a 25K fine in NSW and 5K if you do a home job yourself,

    I dont know the legalities for bikes tough and what state does what.

    Oh yeah, and the comment about being replaced periodically, that is true,

    and its also true that the only people who would ever do that are car enthusiasts, fitting a better highr flowing cat - Metal cats supposedly the go.
  13. excuse my ignorance but
    wont disconnecting the o2 sensor
    mess with the fueling
    and cause it to run rich or lean?
    without running a power commander/standalone cpu
    it usually does with modified cars
  14. As I recall, the ADRs don't specifically require a cat on any vehicle. The emissions ADRs are "performance based" standards and merely stipulate the maximum levels of various gases and vapours under specified test conditions. That said, for most vehicles and manufacturers, a cat is the easiest and most cost effective way to achieve the required performance.

    Up until a year ago, at least, there was no requirement for bikes to meet any emission standards whatsoever apart from generic "no visible smoke" requirements. As such, the removal of a cat from a bike would not affect its compliance with applicable ADRs. I'd be more concerned about falling foul of noise regs as a cat does have a significant muffling effect and the remaining muffler may not be adequate.

    Your best bet is to call your local Vehicle Standards office (part of your RTA) and get the information straight from the horse's mouth. Don't be fobbed off with ifs or buts. They may try to discourage you but they're not permitted to outright lie by telling you it's illegal when it isn't.

    I'd have a look at the ADRs on DoTaRS website too.
  15. No as the system is not a broad band set up and only goes closed loop under cruise conditions. If a Power Comander is fitted you must remove the o2 sensor to get the full benefit
  16. You won't gain much on a modern 600/4. It probably won't do any harm either. You may end up with an unpleasant resonance noise.

    As noted above, there is no legal requirement to run a cat. They only run them because they can with unleaded fuel.
  17. you can do it, but it creates more turbulance in the exhaust and can sap power, best thing to do is to replace it with a full system or have a muffler shop fabricate a mid pipe so the exhaust gas pass smoothly. This is a standard mod for many zx10's as the header pipes are quiet good, remove the baffles from your stock muffler with a a&r baffle kit, ad a mid pipe and you have a full system for less $$. pc3 it and you get close to full system hp