From: kludge@panix.com   
      
   micky   wrote:   
   >In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com   
   >(Scott Dorsey) wrote:   
   >   
   >>AK   wrote:   
   >>>I had an oxygen sensor replaced.   
   >>>   
   >>>Prior to that I got 20 mpg in the city for my CX7.   
   >>>   
   >>>Now I am getting 21.5 mpg.   
   >>>   
   >>>Could that increase be due to the replacement of the O2 sensor?   
   >>   
   >>If your O2 sensor was reading low and causing the computer to run the   
   >>engine too rich, then yes.   
   >   
   >So if now I get codes P0171 and P0174, which means that both banks are   
   >running lean, does that mean replacing the sensors will cause the   
   >opposite of what AK had, richer mixturen and decreased mpg?   
      
   Those codes don't mean that at all.  Those codes mean the computer THINKS   
   both banks are running lean.   
      
   If the computer thinks the engine is running lean, the computer will   
   try to make it richer.  It may or may not succeed depending on what   
   is broken.   
      
   So all those error codes tell you is that SOMETHING is wrong with the   
   mixture, it doesn't tell you anything at all about what it is.   
      
   All the codes are useful for is to tell you something is wrong so you can   
   look at the sensor and actuator plots on the scanner.   
   --scott   
      
   --   
   "C'est un Nagra. C'est suisse, et tres, tres precis."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)