XPost: rec.autos.tech, alt.home.repair   
   From: bobnospam@gmail.com   
      
   On 4/23/2023 10:44 AM, Peter Moylan wrote:   
   > On 24/04/23 04:48, mike wrote:   
   >> Only two things have ever set the readiness monitors for me, one of which   
   >> was to drive for a few hundred miles at one stretch, and back, which   
   >> shouldn't do anything (because I know what a drive cycle entails).   
   >   
   > You seem to be right at the inflection point of the cat efficiency, so   
   > almost anything that affects its efficiency will cause your symptoms.   
   >   
   > That means your real question, whether you know it yet or not, is what can   
   > increase/decrease the efficiency of a catalytic converter in operation?   
   >   
   > Taking your long drive example, I think that long drive might have heated   
   > the cat to the point that maybe that heat temporarily increased its   
   > chemical efficiency. Maybe the same thing happens with water in the gas?   
   > Or, maybe it's not the water in the gas but the fact that the water caused   
   > the cylinder to shut off which caused gas to flow over the cat which might   
   > have again heated up the cat enough to temporarily increase its efficiency?   
   >   
   > You only threw a little gas onto the cat because you kept resetting the   
   > codes so you threw gas on the cat, and then you ran normally hot, and then   
   > you again threw gas on the cat, & you repeated that cycle many times over.   
   >   
   > Maybe that heat:cool:heat:cool:heat:cool:heat:cool cycle increased the   
   > efficiency of the cat just enough over a threshold to stabilize the system?   
   >   
   > All indicators are that you're on the cusp of catalytic efficiency, where   
   > 98% of the time or thereabouts you're just efficient enough, but under some   
   > conditions that you need to figure out (usually temperature & humidity),   
   > you're below efficiency.   
   >   
   > Then the code is set which will reset on its own within three drive cycles.   
   > But once you clear the code, you have to wait for cat readiness to be set.   
   >   
   > If you have the time for your next smog, I suggest you do NOT clear the   
   > codes (because then you add the second readiness monitor to the mix), but   
   > that you let the drive cycle (usually around 50 miles) clear it for you.   
      
   Would any electrically controlled fuel injection engine continue to   
   inject fuel into a cylinder to which it had cut off spark?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)