Ken167

Codes P0430 and P0420 have been on for a while and car is due for smog in a few months. I do have a set of used cats I got from a Lexus recycler they are the primary cats attached to the exhaust manifolds. Im hoping they are good and will clean up the exhaust.

If not then Ill try the O2 sensor extenders (I assume right after the primary cats).

Worst case I will have to go to a Toyota/Lexus dealer for new cats which I dont want to do and be ripped off several $1000!

What else to do??!!

Protholl

Ken167

I tried 2 bottles of OXICAT did nothing

lS35O

Erase the codes then get tested after a couple hundred miles if it doesn't return.

Ken167

I found a Lexus recycler that has the primary cats/manifold for an IS250, will they fit an IS350??

Protholl

Well you gave it a go - wish it had gone better.

FrankIII

I feel your pain, mine's throwing those codes, too. And I just bought it recently.
Look around a bit, at least where I live there are crooked inspectors all over the place...I'm more worried about what riding around with those codes are going to do to my engine.
Good luck

MikeFig82

iTrader: (13)

I've replaced my AWD passenger side with a Walker aftermarket catalytic converter. It was around late 2019 it's still working as intended. The price was pretty cheap at the time. I wish I would've of bought the driver side too. The prices have significantly jumped now. If you are mechanically inclined the work is not that bad. A skilled mechanic can knock the the job out with some after market cats in no time.

If you get a good OBDII bluetooth adapter, and Fusion app. You can constantly monitor what the sensors are reading. I drive with it on daily viewing how everything is working. This will help you avoid costly problems down the road if you catch them early on.

lS35O

Can you recommend a good OBDII bluetooth adapter?

MikeFig82

iTrader: (13)

I personally use VEEPEAK:

https://www.clublexus.com/forums/is-...-pid-pack.html

Ken167

Is the Walker a direct fit OEM replacement? Is it the one piece cat attached to the exhaust manifold??

MikeFig82

iTrader: (13)

The Walker fit just like OEM. No issues mounting. I'd recommend getting OEM gaskets, for the head side and lower Y pipe. They supply gaskets, but the Y pipe side is too large. The OEM Y pipe gasket has tabs that you open to help it from falling off the manifold. When bolting everything back up.

Just make sure they are carb legal for California. I think I saw a note that read not legal in California.

FrankIII

I know these things are bolted right there at the manifold, but I'm wondering if a skilled muffler shop could cut those two front cats out and weld in a pipes? Sorry if this has been covered, I'm a noob.. and dealing with the same situation.

MikeFig82

iTrader: (13)

It may be difficult. There is not much room. Then again it would take a skilled welder. The cats sit pretty mush next to the firewall. I can't remember how close though.

AMIRZA786

If they are not CARB Legal in California, than buying them would be moot, at least for the purposes of passing smog. His car would never pass smog, both in the visual inspection as well as during the diagnostic phase