Does removing or gutting the catalytic converter improve performance of the 5vz? They make a thingy that hooks up to the rear O2 sensor that emulates the signals of a good cat so the OBD is happy. I'm just looking to get a little extra oomph from my truck.

Thanks

I really hope you don't work in the reactor room ... if that answers your question.

The short answer is removing it is a bad idea and will not provide any long term HP gain.

If there is a gain it would be very minimal,in Kalipornia it is illegal to delete or hollow out the internal.

Its probably illegal here in NJ, but as long as the OBD reads clear and they see a catalytic converter when they image the underside of the car, all is good. A non OBD2 car would be a different story

W/O a cat wont you still fail a emissions test, nvm if the OBD is happy or not?

Removing the catalytic converter is illegal in every state.

All that takes place in NJ inspections is a look underneath the car to see if there is a cat and an OBD2 scan. Of course it is illegal. Its also illegal in most places to windshield mount your GPS.

Windshield mount laws are generally not enforced but lets just say you get pulled over. Most likely they will tell you to remove it and drive away without a ticket. If for some odd reason the cop gave you a ticket for it, I am sure the fine will insignificant but probably easily dropped in court. On a side note, oddly enough mounting it on your dash is legal in all those states but a dash mount blocks more of my vision then where I mount it on my windshield. Luckily it is not illegal in NC but it is in SC and Ga (where I am from) and I was never aware of it until now.

Catalytic converter is a much different animal. First off, it is a federal law that was passed in 1988 with the EPA Clean Air Act and carries much higher penalties.

Fines for the owner can be up to $2500 and for the institute that removes it, up to $25,000

Chances are you won't get caught unless there is an inspection in your state.
However, is it really worth the risks and headaches for something that won't lead to much gains? Even if you gain anything at all, any notice to those gains would be purely placebo.

Here is the law if anyone is actually interested in reading it.
Title II | Clean Air Act | US EPA

They also test the gas cap,last year my 00 Tundra passed visual and scantool but failed for a friggin' cap. Next year when the 4Runner is going to inspection I'm bringing the new Tundra cap with me LOL.

But to answer your original question,very doubtful you'll gain anything if the cat isn't already damaged. These aren't the super restrictive cats from the 70s and 80s.

Not only would you not even notice it performance wise, the truck would stink like high hell and you could probably never have your rear window down again.

If you're that concerned get a hi-flow cat.

Exactly - I had one go bad on my 2nd gen and it smelled like a dump truck all the time. Couldn't roll down the back window or it was really bad. You won't see any noticeable gains (though maybe 2-5 HP on the dyno?). It will also be much louder. The cat forms part of the exhaust system and reduces noise quite a bit. When it went bad on my 2nd gen I hollowed it out (until I replaced it - the guts came loose inside and rattled like crazy) and it was quite loud and annoying. It sounded like a beater with a broken exhaust pipe.

If they are going to do a visual inspection and OBD scan to make sure the emissions system is in place, I'm assuming they are gonna drive the truck into a shop themselves. It will be very obvious there isn't a working cat on the vehicle from the smell.

You are more likely to get a windshield obstruction ticket then an emmisons ticket.

How many federal law enforcement officers are out there in all pulling cars over for checking federal law.

And as for federal automobile laws that get broke on this forum all the time.

Bumper height restrictions
Bumper crumple zone restrictions
Headlight violations (hid swaps)
DOT compliant wheels
exhaust decibel limits
DOT compliant driving lights and tailights
Frame height specification

And probably several others but there is no agency out there enforcing these laws.



The EPA is just more governmental bureaucracy that is draining the country. They are closing down the last Lead smelter in the united states this month. People lose jobs, Lead products will have to be imported form overseas, batteries will cost more, bullets will cost more and everything else with lead will increase or disappear.

Yet - If you have big money or well connected IE Dupont, you can keep polluting and caring on with no consequences.

It doesn't have to be a federal cop that pulls you over and gives you a ticket.
Besides, like I said, it is unlikely you will get a ticket for it. (maybe you missed that part).

I have no issues with laws being broken and all those other laws you named actually give you gains in some area. My point was that removing the cat won't give you any noticeable gains (if any at all) so it isn't worth taking the risk.