XPost: sci.electronics.repair, alt.home.repair   
   From: this@address.is.invalid   
      
   On 23-04-2023 21:04 Bob F  wrote:   
      
   > Or, did the water clean up the catalyst?   
      
   That's a good question.   
   Is there some chemistry that running water through the cat cleans it up?   
      
   The water issue was new as that was a complete accident that I had an empty   
   tank and I had to take someone to the airport all of a sudden so I used a   
   five gallon container of gas that was outside and it turned out to be old   
   and it happened to have a lot of water in it as the cap was leaking inward.   
      
   The 2004 Mitsubishi Lancer 4-cylinder tiny engine has always had this   
   problem since I bought it as the previous owner sold the entire car to me   
   for $200 knowing it needed a new catalytic converter & much other stuff.   
      
   A mechanic told him that was the reason for the P420 code, but what I did   
   when I got the car was put a new oxygen sensor in and that helped for a   
   couple of years to get it through smog but it still is hard to set the   
   readiness monitors. I know all about the drive cycle but it's got nothing   
   to do with that as it takes months of use to set the readiness monitors.   
      
   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).   
      
   The other thing happened to be the water in the gasoline fiasco, where the   
   tank is something like ten or so gallons, but I put in five gallons of a   
   gas:water mix, which I used up and then refilled with clean gasoline.   
      
   Once the codes see a misfire of 1 in 200 revolutions, the engine control   
   module turns off the electricity to that spark plug, and the only way to   
   turn it back on is either to shut down the car or reset the codes.   
      
   It turns out that clearing the codes while driving works perfectly. There   
   is a seven second delay between stumbling, clearing, and the codes gone.   
      
   I know this because I had the OBD tester in my lap for hundreds of miles   
   over a period of a couple weeks where I reset the code I don't know how   
   many times, but probably a few hundred times in a single tank of gas.   
      
   What's weird is that this issue of the P0420 cat code and the inability to   
   reset the cat read monitor has happened for many years (probably three   
   smogs, so that's six years) but its character changed completely after the   
   water-in-the-gas fiasco with the hundreds of reset actions.   
      
   Now there is no P0420 code and the readiness monitor set it self nicely.   
   How did that happen?   
      
   I was thinking that there might be a database inside the engine control   
   modules of the last fifty or so codes, where I used them all up by clearing   
   more than those fifty or so times, but your idea that the water in the gas   
   chemically cleaned out the cat sounds better as it's kind of like a   
   'seafoam' treatment, of sorts.   
      
   Is there any chemistry backing up that idea that the water cleaned the cat?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)