Possible Aftermarket Catalytic Converter Trap

[feelgoodbags]

Just a heads up if you are looking at an aftermarket catalytic converter for your 100 series/LX 470. I bought an aftermarket federal (non-CARB) Magnaflow direct fit OE and replaced the burnt out cheap aftermarket cat that the prior owner installed on my 2006 LX 470.

I bought the federal cat rather than CARB because I don't live in California.Within about 50 miles, it threw P0420. For a few months I have been looking for exhaust leaks and replacing sensors hoping that was the problem but no luck.

I just discovered what I think might be the true problem. Even though I don't live in California, my LX 470 was originally destined for the California market. I have not confirmed this with Toyota, but apparently if the vehicle was going to California, the ECU was programmed to be a little bit more stringent on the cat readings. So, because of the more stringent ECU standards, the federal cat that I bought is likely not meeting the standards. Here is a picture of the catalyst decal on the inside of the hood that shows the California issue.

So, if you are looking for an aftermarket cat, just be aware that even though you might not live in a CARB state, if your vehicle was originally required to be CARB compliant, it might still need a CARB cat.

Again, I have not confirmed this with Toyota but it seems to fit my situation.

Someone who's smarter than me please chime in if this is incorrect. Thanks!!

 

[feelgoodbags]

Good observation, but I’d verify the emissions label/VIN application before concluding the ECU is using a special destination-market threshold. For P0420 after a cat replacement, first rule out a small exhaust leak near the manifold/cat or a damaged/swapped downstream O2 connector, then check fuel trims/misfires and compare the upstream/downstream O2 behavior at steady cruise. A new converter can also be underperforming or simply be the wrong emissions application. If the underhood label calls for California emissions, match the converter to that configuration even if the truck now lives elsewhere; otherwise the federal unit may be the correct application.

Thanks for the guidance! Where is your shop located?