1996 Lexus LS 400 - Can I remove the Emissions control equipment

Can the catalytic converter be removed from 1996 Lexus LS 400 and the engine will run ok?

It’s a $25,000 fine if you get caught removing it…

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Don’t know, never tried it; but engine would probably run ok except for drivetrain computer complaints about missing/incorrect O2 sensor signals. . Computer may be quite upset about those, & put car is limp mode. Suggest best course is to not attempt this idea, fine $$$ really big. Worry about fine is never-ending. If you later take car to shop for brake pads, the techs there may spot the missing cat & turn you into the feds. Why would they bother? The feds may offer a substantial reward.

The engine would run OK but the check engine light would always be on and you; be violating FEDERAL law to do this (that $25,000 fine!). And if your state has emission testing you’d fail.

I’d like to see how good his exhaust looks after he removes cats

That era LS400 is one of the few old luxury cars that is remarkably reliable. There are 3 cats on it, I’d spend the money to fix whatever the problem is, or I’d sell it and get a car that works.

How many miles are on it? How’s the rest of it, condition-wise? Use much oil?


If the OP removes the cats, he won’t need no stinkin’ exhaust.

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Its your car do anything you like.


Anything to substantiate that, or just guessing again?


I was going to say what happens if someone says that their catalytic converter was stolen? That got me thinking. What if thieves stole catalytic converters and clamped a straight pipe in there as a replacement, so the driver wouldn’t know that it was stolen until the OBD II test discovered it?

Some sophisticated thieves changed my catalytic converter for a straight piece of pipe!

1996 is the first year that requires on board testing of the catalytic converter. I beieve some models of “1996” vehicles were made in 1995 and don’t have this system.

That would take a lot longer than it would to cut the cats out. IMO a thief that does that would be unsophisticated.

First off, NO thieves would DO that. Second, the Check Engine light would be immediately turned on. Third, the victim would complain of a “different” sound because the cats were gone.

The emissions inspection includes a visual of the equipment as well as an OBD2 check. The owners argument would be the equivalent of “my dog ate my homework” :roll_eyes:

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let the road take care of the exhaust system for you.

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There you go again, being both logical and factual.
We will have none of that!
Instead, we should just succumb to bizarre speculation based on a total lack of both logic and factual information.

Get with the program, man!


If a catalytic converter thief were to replace the stolen converter with a clamped in straight pipe, the thief would have to report the cost of the straight pipe as a business expense on his income tax.


I would not remove emissions control equipment, however all this talk about $25,000 fines really misses the point. The Feds are not going to go after Joe Blow who removes/defeats emissions control equipment on his own personal vehicle(s). They are going to go after anyone who is doing this as a service for others, publishing information online about how to do it, or selling products (such as modified PCMs or “tuning” software) which are designed to defeat emissions controls.

If someone lives in a state where emissions testing is not required, and they don’t mind ruining the value of their car, then there is really nothing to stop this person from removing/defeating/“tuning out” their emissions control equipment.


these are O2 sensor bungs welded on to reposition O2 sensors to fool the computer. this is on a LS400. Don’t know if it works

As guaranteed by the 5th amendment to the US Constitution I exercise my right to decline to answer your question.

The second you drove it…One of the O2 sensors would sense something’s wrong and throw an ECU code (Check Engine Light). Also, the exhaust would be noticeably louder. You might be fooled, but the rest of us from the forum wouldn’t.

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