P0420 just popped

[Fahrenheit]

Car runs fine, no shutter or hesitation. Gas mileage doesn't seem to have changed but i'm not keeping track. Gonna try the spark plug non-fouler thing, any down sides to that? Also are all the threads on them the same? Just walk into an auto zone and ask for one?


Rather that then a 160$ cat (cheapest on rock auto)

 

[Scottydoggs]

if you need a new cat, buy a cat. you can find them cheaper then that. sooner or later it will clog up.