p.s. I would make the dealer's life miserable until they do the right thing. If they are a corporate store, I'd contact corporate, if independent, I'd find a way to get to the owner. Owners(with some exceptions) don't like their dealerships to have a bad reputation.

 

Yes it is.

 

Yes, and one must also make sure there are no dogs in the cats.

https://wheels.blogs.nytimes.com/201...s-in-its-cats/

 

If things don't work out then do what someone else did.

Walk outside the dealership on public pathways and keep moving with a board in your hand that says. "I bought a car from here and had $3K repairs in 50 miles". Make sure people driving into the dealership see it.

I can't find link to the story or post now but it was hilarious. I think in that case it was a transmission problem but worked like magic.

 

An important part of due diligence that most people don't do, that applies to all used cars (not just the LS430), is to plug in an OBD2 reader to ensure that all 3-7 drive cycle monitors (depending on make/model of car) have been completed. It is common for used car dealers to reset the computer right before your test drive and/or again before you take possession. Therefore, you won't ever suspect anything is wrong, but approximately 10-100km after the reset - after the various drive cycles have completed and the monitors have been set - you will get the check engine light. You may have been a victim of this unscrupulous used car selling practice.

Two people I know from two different cities had this happen to them on their used car purchases - I personally diagnosed and repaired both cars. The problems (defective evap box, evap solenoid, O2 sensors, ignition coils, fuel injectors...) definitely existed before the purchase but since the computer was cleared and these problems didn't result in any obvious driveability issues, they couldn't tell anything was wrong before buying.

I have previously described the LS430's OBD monitors at https://www.clublexus.com/forums/ls-...ml#post9626651.

Even on my 02 LS430, when I had a hairline crack in the Y-pipe caused by salt accumulation under the heat shield, causing a catalyst efficiency low error (P0420 / P0430), I could reset the computer and drive for 10-50km before the light would come back. Before I found the Lexus instructions for setting the evap system monitor, I drove over 100km over 2 hours trying to get that monitor to set. Then I looked up the exact procedure (after which I posted it per the above link) and it took 10 minutes and no driving to set it. All that to say, you could drive for awhile without knowing there is a problem if your driving conditions don't meet the criteria for setting the monitors.

To pass emissions testing in Ontario, it isn't enough for the check engine light to be off - they need to see that all OBD2 system monitors have been completed. The various system monitors the e-Test checks for are: Misfire, Fuel System, Comprehensive Components, Catalyst, Heated Catalyst (n/a for LS430), Evaporative System, Secondary Air (n/a for LS430), O2 Sensor, O2 Sensor Heater, EGR System (n/a for LS430), and AC System (n/a for LS430).

Many inexperienced shops will tell you to replace the cat when receiving a P0420 or P0430 - they don't realize that an invisible tiny pinhole leak is enough to cause this catalyst error. I would ask them to thoroughly check the exhaust system, which means removing the heat shields, covering the exhaust tips, and checking all gaskets and tops of the pipes for near invisible leaks.

I think it's rare for any of the 3 catalysts in the LS430 to fail. As Jabberwock mentioned, if bad O2 sensors caused the engine to run rich for hundreds/thousands of kilometres, then that would make catalyst failure more plausible.

 

^^ Great advise.

OBDII adapter doesn't cost much and even the torque Lite app gives you pending codes.
Codes in 50 miles pretty much indicate that the codes were reset.

I did checked OBDII codes before I bought my LS460L recently even though the seller said there were no codes.