Hi Scotty,
Longtime fan first time advice seeker.
I have a 2005 Toyota Highlander LTD 3.3l AWD. "Butch" has 243k on him and at least the last 75k have been hard miles. I was out tooling around the Colorado Rocky Mountains for the day today. I got caught up in a cone zone for 15ish min where I had to idle on my way home. After we got going again I dropped back down into overdrive and just as I had done that codes tripped. I made it to the nearest O'Reilly's (who uses a sucky OBDII scanner) and P0420/Bank 1 came up once and P0430/Bank 2 came up twice over the 15 miles it took to get to O'Reilly's.
I don't know my 1st bank from my 2nd but what I can tell you is I put on a new (Amazon) Cat Labor Day weekend on the front side and it nas ran with no problems until now.
I'm concerned that since both Bank 1 and Bank 2 tripped at the same time and just as i was switching in to overdrive my issue is much further upstream than my cats and/or AF/O2 sensors. I did notice a strange odor that some may call rotten eggs but it was different than that to me.
Your thankful fan,
Mike Flynn
Denver, CO
Well right in eggs a sulfur burning in the catalytic converter. You might have gotten some bad fuel. But realize Cadillac converters on those things never go out by themselves. And if you replace the cat, you're not fixing the underlying problem that made it go bad in the first place. So many things can make them go bad from burning oil running rich running, lean lots of stuff
