• xthexder
    link
    fedilink
    English
    arrow-up
    1
    ·
    1 year ago

    I’m not talking about check engine lights in general, but specifically all the emissions control sensors that are mandated by the government, and will throw an engine code for emissions (which can then fail you on an inspection if your state has them). Catalytic converts weren’t even a thing in 1968, so “onboard computer diagnostics” isn’t talking about the same thing.

    A car from 2000 vs 2020 have very different emissions requirements from the factory, since the laws have changed over the years. It makes sense that they’d be treated differently for their polluting potential.

    • gayhitler420@lemm.ee
      link
      fedilink
      English
      arrow-up
      1
      ·
      1 year ago

      Still though, my 2000 pathfinder had that. It would literally throw the obd2 code for catalyst bank efficiency which basically meant either there was a hole in the exhaust keeping the gasses from getting to the catalytic converter or the converter was passing gasses without catalyzing them.

      When the catalytic converter gets clogged you get all the different “hey, you’re running lean!” type codes.

      My truck used the same process to figure it out and turn on the check engine light when it saw that you weren’t getting good enough combustion (efficiency is in almost all circumstances the maximum amount of power you can get!)

      I’d be interested to know what requirements you’re talking about, since they vary by place. I know at one point California had mandated dyno testing which people hated but it’s the real best way to both evaluate emissions and see if the car is running worth a crap.

      • xthexder
        link
        fedilink
        English
        arrow-up
        1
        ·
        edit-2
        1 year ago

        The more I read into emissions requirements, the less I’m convinced there’s a meaningful difference between a 2010 and 2020 engine’s emissions system. I retract my original statement that a 2010 Polo wouldn’t have the same emissions equipment as a newer car. I suspect a newer engine would still have tighter requirements for sensor values though based on the constantly evolving emissions laws.

        California has made their emissions requirements stricter and stricter every few years, but it seems like most of the big changes were pre-2000 that I could find (or future like the upcoming phasing out of ICEs).

        Just as a summary of the emissions systems I was considering along with catalytic converters, which it turns out have all been around a long time:

        • Evaporation control system
        • Exhaust gas recirculation
        • Crankcase ventilation (PCV)
        • Secondary air injection
        • gayhitler420@lemm.ee
          link
          fedilink
          English
          arrow-up
          1
          ·
          1 year ago

          What you’re saying is my understanding too. All those things are 80s tech that back then operated in separate isolated closed loop servo feedback when working right and pissed everyone off when something went wrong because they couldn’t just go out and fuck around with the carburetor until it worked right.

          Part of what made obd2 so great for so long was that it gave you the actual measurement to pair with a symptom that would tell you what to test to figure out what part was messed up.