installed and been driving about 150 miles and no CEL yet... I figure it was worth the 5 bucks to just see if I can get rid of the CEL before buying an O2 simulator.

so yeah, the CAT is cooked I assume, I am leaking oil from my valve stem seals so its probably pretty nasty in there.

when I pulled the o2 and cleaned it, there was a fair amount of oil on the outside, but the inside seemed clean so I added two defoulers, threw the sensor back on and called it a day.

IF it was going to come back on, how long would it take for the ECU to pick it up again?

P0420 is "Catalyst System Efficiency Below Threshold (Bank 1)"

edit: this mod essentially just moves the sensor back far enough to pull clean air in for the testing for anyone unclear on what the point of the mod is.

 

i did this to my car back in march.. havent seen the code since.