So this is time number 4 since the car was shipped that the CEL has come on for the 0420. Does anyone know what would cause 3 cats to go bad? The most recent in about 6k miles or so? Supercharged with the 9.5 pulley and the trd tune....

 

excessive heat? Just spitballin here

 

I dont beat the car that hard too often. When the light comes on its always when im at about 45mph in 5th gear, so about 2300 rpm.

 

excess heat killing the cat?

hell, why don't you just get an aftermarket header, who needs a cat? lol.

 

I need a cat thats who!

 

my cat failed on me a little while ago as well and i am also supercharged with no other engine mod besides trd axelback

 

i had an 0420 recently too. a shop by me was blaming all the extra ethanol from burning too hot...in all cars.

 

idiot! there would have been a widespread issue on the places that had the 10% added a while ago before everyone else did it.
of course this is just my opinion and im not the expert....

 

Doesn't running too rich kill your cat? If that's the case and you are running an atermarket pulley... you might want to think about getting a piggyback to tune it.

 

its been my understanding that the 9.5 pulley doesnt make the car run richer then stock but leans it out since the trd safe tune is run a little rich to begin?

 

get a catless header get to spark plug defusers and put it under the downpipe o2 senser and it should go away no cel light my two cents.

 

are you calling me an idiot? or the shop manager?

regardless... all i know is when i drove in with my code he called it "cat day" because he had 6 come in...all makes/models..a corvette, and an audi with 60k miles. Mine had the fewest miles. His feeling was that he was seeing more 0420's over the past year versus prior.

And it seems that everytime i go into a shop, someone is getting a cat replaced.. i can't put a finger on it..just relaying the theory. it does not appear to be limited solely to scion..so it could be something in the gas.

 

no i wasnt calling you an idiot. maybe its something where you are. but it sounds like there would be a whole national problem with cats burning out, and it would have come up in the places that rolled out the 10% before it was national.