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  • Catalytic converter that catalyzes?

    I have a used Catco and flunked emissions (Hydrocarbons). I am pretty sure the cat isn't doing its job as its a pretty well used and high-flow. The interwebz tells me Catcos can die in a few thousand miles, and even faster if backfired on or run through a rich motor. Any suggestions on an oem fitment cat that actually does the job? Note I don't care about flow when it's on. I want to pass the sniffer.

  • #2
    I don't know about the size on the S13/S14 ones, but a B14 oem cat has 2.5" flanges on it, which worked great on my Maxima with moderately built engine and JWT ECU.
    Originally posted by SoSideways
    I don't care what color they are as long as they are LONG AND HARD.
    '04 G35 Sedan 6MT- The DD
    '96 240SX- The Track Toy

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    • #3
      if you are using the cat for smog only,
      buy a new catco,
      Pass sniffer,
      remove new catco and shelf it,
      replace with either old catco that is shot, or a tube sock
      I am SKULLWORKS

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      • #4
        Originally posted by Tower240sx View Post
        if you are using the cat for smog only,
        buy a new catco,
        Pass sniffer,
        remove new catco and shelf it,
        replace with either old catco that is shot, or a tube sock
        Pink sock?
        '18 Chevrolet Volt - Electric fun hatch for DD duty!


        DefSport Koni Sleeve and Spring Perch Buy!!!
        http://www.nissanroadracing.com/showthread.php?t=5902

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        • #5
          no, that crunchy yellowish-white one you keep under the mattress.
          Originally posted by SoSideways
          I don't care what color they are as long as they are LONG AND HARD.
          '04 G35 Sedan 6MT- The DD
          '96 240SX- The Track Toy

          Comment


          • #6
            Dude, you're over in Rockville right?

            I could just lend mine to you for a bit...


            Also, idle test is MUCH easier than the old rollers. Those things sucked hard.
            '95 240sx

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            • #7
              Originally posted by gawdzilla View Post
              I have a used Catco and flunked emissions (Hydrocarbons). I am pretty sure the cat isn't doing its job as its a pretty well used and high-flow. The interwebz tells me Catcos can die in a few thousand miles, and even faster if backfired on or run through a rich motor. Any suggestions on an oem fitment cat that actually does the job? Note I don't care about flow when it's on. I want to pass the sniffer.
              Did you make sure to heat it up real good? you want to run the car under a high load for 10 or 15 minutes before you go in for your test, I know this helps a lot with one of the parameters, I forget if it is NOx or what, but I know it does make a huge difference.

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              • #8
                getting the engine nice and hot will make hydrocarbon emissions lower, but will raise NOx. NOx goes up with exhaust temp, HC goes down.

                Also take a look at your ignition timing and EGR. Advanced timing and a blocked EGR are both common go fast mods and will fubar emissions. dial your timing back to stock and unblock the EGR if you've done anything to it.
                Originally posted by SoSideways
                I don't care what color they are as long as they are LONG AND HARD.
                '04 G35 Sedan 6MT- The DD
                '96 240SX- The Track Toy

                Comment


                • #9
                  Originally posted by Matt93SE View Post
                  I don't know about the size on the S13/S14 ones, but a B14 oem cat has 2.5" flanges on it, which worked great on my Maxima with moderately built engine and JWT ECU.
                  The S14 and B14 are the same. I've switched mine out.

                  Comment


                  • #10
                    Originally posted by Matt93SE View Post
                    getting the engine nice and hot will make hydrocarbon emissions lower, but will raise NOx. NOx goes up with exhaust temp, HC goes down.

                    Also take a look at your ignition timing and EGR. Advanced timing and a blocked EGR are both common go fast mods and will fubar emissions. dial your timing back to stock and unblock the EGR if you've done anything to it.
                    Catalyst efficiency goes up with increasing temperature, which is the reason to get everything as hot as possible.

                    Peak cycle temps influence NOx creation, and they typically don't change much once an engine is "moderately up to temp."
                    '18 Chevrolet Volt - Electric fun hatch for DD duty!


                    DefSport Koni Sleeve and Spring Perch Buy!!!
                    http://www.nissanroadracing.com/showthread.php?t=5902

                    Comment


                    • #11
                      Best bet on the most effective(emissions-wise) catalytic would be a California spec cat. It will cost more, but that is partially due to the fact it has more precious metals(catalyst) in it. I had the same problem eariler this year, high HC with a high flow magnaflow cat. Replaced it with a CARB spec cat and it passed with very low HC numbers. Here are some photos that compare the 2. The dirty one is a 2.5" high flow magnaflow purchased from PDM. The new is CARB legal cat which is supposed to be 2.5" in/outlet. You can see that the CARB version has smaller ID as well as more catalyst honeycomb that the exhaust must pass through.


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                      • #12
                        Originally posted by ta2maki View Post
                        Best bet on the most effective(emissions-wise) catalytic would be a California spec cat. It will cost more, but that is partially due to the fact it has more precious metals(catalyst) in it. I had the same problem eariler this year, high HC with a high flow magnaflow cat. Replaced it with a CARB spec cat and it passed with very low HC numbers. Here are some photos that compare the 2. The dirty one is a 2.5" high flow magnaflow purchased from PDM. The new is CARB legal cat which is supposed to be 2.5" in/outlet. You can see that the CARB version has smaller ID as well as more catalyst honeycomb that the exhaust must pass through.
                        Thanks this information is helpful. I am pretty sure that 1) the Catco isn't great to begin with, and 2) It may be busted. A "good" cat is what I need.

                        ta2maki - where did you purchase? fleabay?

                        Both s14s I've owned ('95) came with empty cats underneath the car from the factory. I am pretty sure on the 95-96 it is an empty cat, and the only cat on the car is right off the header. I believe the 97-98s have a "half-cat" underneath the car, and the s13s/b14s have a full cat beneath the car.

                        Sleepy - I'm in Rockville, yep. appreciate the offer, but honestly I think it will be a waste of time to try out. Not to mention the next test won't be free. I've already failed twice.

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                        • #13
                          Unless you bought the car new from the factory and pulled it out to finda hollow cat, then your cats blew apart. All cars made since the early 80s or so are required by law to have cats, and nissan didn't put an empty can there. (those empty cans really rob power due to the gasses expanding, then bottlenecking out the other side. you're better off with a real cat to help maintain laminar flow through there or with a straight pipe.)

                          anyway, my '96 actually material inside the rear cat when I bought it. Since it was OBD-II, there was another in the midpipe.
                          After 6 months of beating the bejeezus out of the car, it started running bad and I heard a rattling sound sometimes. whenever I banged through the gears, I'd lose about 50% of my power and then I'd see a huge puff of smoke behind the car and the car would run better. If I rolled onto the throttle after a shift, that didn't happen.

                          Finalyl I pulled the main cat out and the catalyst material that was left was about the size of my fist and just rolling around in there. what it was doing on hard shifts was rolling to the back of the cat and plugging the exhaust, killing the power.

                          Long story short... Originally, these cars all had cats from the factory in the main cat position. OBD-II cars had an additional one in the midpipe. I think the '95s also had them since they were preparing for OBD-II compliance in '96, but the S13 chassis did not.
                          Originally posted by SoSideways
                          I don't care what color they are as long as they are LONG AND HARD.
                          '04 G35 Sedan 6MT- The DD
                          '96 240SX- The Track Toy

                          Comment


                          • #14
                            Why not just run 2-3 cats in a row? Ghetto I know but it will work (or so I'd think)
                            'Slicks on a car show me you care - broken axles show me you're trying'
                            [I]Nitrous Rental Cars - Turbo Festivas - Vehicular Lunacy[/I]
                            [SIZE="3"][B][url]www.sloppymechanics.com[/url][/B][/SIZE]

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                            • #15
                              wouldn't pass visual inspection probably....
                              Originally posted by SoSideways
                              I don't care what color they are as long as they are LONG AND HARD.
                              '04 G35 Sedan 6MT- The DD
                              '96 240SX- The Track Toy

                              Comment

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