MarcelL2o6

I have 04 gs430 with like 142000 miles recently my check engine light came on for code p0420 i was wondering is there anything i should replace before getting a whole new catalytic converter

shwalker07

Exhaust leaks can also cause this code too especially around the flanges. I had this code due to a small exhaust leak in the past but I got rid of that code it with a $8 o2 sensor spacer which works if you do not have to do visual inspections for emissions because you will fail with that part installed.

kevin3344

Usually with P0420/P0430 check the exhaust leak first, then 02 sensor, and lastly your cat. I got the P0430 and it was an exhaust leak on my y-pipe. If you search you'll find a lot of threads where people replaced their cats only to have the code return.

JustChill

iTrader: (9)

hey shwalker, got a link to the o2 spacer? and do you put in on the downstream or upstream?

FrankT

Here is the one I've used, this one requires you to drill the hole with a 1/2" drill bit on one spacer for your o2 sensor...

shwalker07

The thread size is M18X1.50 and you will see a lot on ebaymotors. I am running the stainless steel style ones with the 90 degree adapter on both of the rear o2 sensors after the catalytic converter. Never use these on your upstream sensors.

kaliehulum

I have a code that is B2791 I'm not sure what this code means of possible

Jamison1

I have changed the 02 sensors on mine, but my 2003 gs VSC light and engine light are still on. Also Solenoid was an issue I guess ? mine has 142,000 miles as well

podda

My 2017 lexus gives this error, i examined the error and p0420 code shows cat. converter problem, i ordered and was replaced the new one and code is gone...