I have been battling a P0420 code. I was considering having the dealer reflash the pcm per TSB 04-15-16 to increase the switch ratio limit. According to the sticker I have EXE1 and I found on motorcraft.com that EXE3 is the latest and greatest. Only problem I have now is that the tsb calls for .4 hours labor but the dealer said they will only do it for 1.5hrs of labor. Too bad its not still under warranty.
I just got an Actron 9180 scanner and have been learning all the things it can do. According to the diagnostic test I can run with it the bank 1 max switch ratio is .4056 and I am actually at .42, thus the P0420. Looking at the real time oxygen sensor readings both upstream sensors fluxuate between .1v and .8v and neither look lazy. The bank 1 downstream fluxuates between .3v and .8v and bank 2 downstream .06v and .1v. My understanding is once the catalyst lights off the downstream sensor should level off around .45v. Doesn't make sense to me why the bank 2 downsteam is so low? As for the bank 1 seems like the catalyst is not doing its job at all. I am thinking about trying the anti-foulers to lower the switch ratio under the limit. Sorry for the long post. Any info is much appreciated.
I just got an Actron 9180 scanner and have been learning all the things it can do. According to the diagnostic test I can run with it the bank 1 max switch ratio is .4056 and I am actually at .42, thus the P0420. Looking at the real time oxygen sensor readings both upstream sensors fluxuate between .1v and .8v and neither look lazy. The bank 1 downstream fluxuates between .3v and .8v and bank 2 downstream .06v and .1v. My understanding is once the catalyst lights off the downstream sensor should level off around .45v. Doesn't make sense to me why the bank 2 downsteam is so low? As for the bank 1 seems like the catalyst is not doing its job at all. I am thinking about trying the anti-foulers to lower the switch ratio under the limit. Sorry for the long post. Any info is much appreciated.