po1qw

iTrader: (2)

So I got the check VSC light with the code P0420 Catalyst System Efficiency Below Threshold (Bank 1) took the car to the shop and they said my catalytic converters are bad and it need to be replaced, was wondering if the original cats are cover under warrant so I can get the job done back at the lexus dealership( gotta save some money times are hard ). If anyone has insight or advise for me feel free to help me out

car is Is250 awd 2008 with 51000 mileage

To make situations even worst my inspection sticker is expired, ate one ticket alrdy getting an EXPENSIVE cup of coffee ..not interested in another one

flowrider

iTrader: (9)

Did some research for you. You should be covered. See attached from Lexus warranty booklet.

Lou

po1qw

iTrader: (2)

thanks for the tip i'll see tomorrow and have talk with lexus

Bichon

Often the P0420 code on our cars happens when small holes develop in the Y-pipe ahead of the catalytic converters. The holes are difficult to see, since they happen underneath the heat shield, but you'll notice that the car is a bit noisier; particularly noticeable when starting the car in a garage with the driver's window open. In either case, you should be covered by the emissions warranty.

Mokey

Yep, had the same code show up with the check engine light on and the message on the dash to check VSC and the tech said the same thing. Seems like a common issue. Guess SOMETHING finally had to go wrong after 120k miles since 2006! What a great car. And loving how tail happy my car is now too with the traction disabled,

kensteele

got the same code and problem but i am out of warranty by over a year and at least 10k miles over. took it into dealer, they want $2k to fix and garage wants $1.3k to replace cc (talked to them over the phone only). any advice on what i should do from here? yes it does sound a bit louder in my garage, should i have it inspected by the garage?

i'd rather not pay $2k for replacement repairs that may not be necessary and i'm not happy with my dealership right now since they tried to hook me with the airbag light until i complained to lexus. code has been cleared several times but it keeps coming back on (check vsc) and i've tightened the gas cap. thoughts?

in the meantime, i'll keep searching other threads.

p.s. i can't remember if i have p0420 or p0430.

synrgy350

I had the same exhaust leak and I had an exhaust shop weld the hole and it's been holding up well for over a year now. Cost me $20.

lilStig

iTrader: (5)

I have the same issue. I paid for 2 days access to the Toyota tech information site. Downloaded couple pdfs to troubleshoot the issue to find out exactly what's the problem and also ordered a chinese techstream kit from amazon. PM if you guys need help. May decide to create a DIY when I'm done.

TheSenator

iTrader: (1)

The downstream sensor is reporting different frequencies from the upstream sensor on that bank.
My 0420 code was not from holes, but from a clogged cat after a decarb at 90K miles.

I gutted the stock cats, used 90 degree 02 non-foulers with the stock o2 sensors.
$30 for the foulers
$100 to my tech

Passed inspection in Tx, no codes since.

kwillms

A few months ago I had a decarb at 95k miles (oil change place upsell) and very shortly after my IS 250 started throwing p0420. I found a video about the non-foulers, but it sounds like the cat was clogged, but you kept using it? I'm also in Texas, so I doubt it's holes in the exhaust...but worth looking into.