simonyu

I have P420, P430 codes on my LS400, 1996, check engine light is on . Do I have to change both catalytic converters which would cost more than $1000? Could I just change O2 sensors or the converter gaskets and how do I verfiy that before I purchase these parts

LiCelsior

iTrader: (32)

check to see if theres any leak at the converter gaskets.

boris

Simon, I have a 95, had to replace cat about 2 years ago. It was done by a very trusted mechanic and he used A&B cat. I have not had any issues. But true first make sure that the other parts are not causing the code to go off. I had replaced first the oxygen sensor to no avail. I mostly due my own work but was in a hurry so had him due the cat. Hopefully this helps.

PureDrifter

iTrader: (10)

replace the gaskets first, clear the codes, then drive it. if that doesnt work, replace both the post cat O2 sensors. THEN LASTLY replace the cats if those 2 fixes don't help.

jcrome04

Got any part numbers off hand for the Cat gaskets?

I have these same codes.

I you don't have them I guess I can put in a little more effort and call the Lexus dealer haha