Topic: Pro's and Con's of removing catalytic converter?

[lqdtrance]

What are the pro's and cons? I don't need to pass emissions anymore so I was wondering. Thanks.

[aka-justin]

On a 4cyc, it doesn't have a down stream O2 sensor, so it won't know or really matter.

On a 6cyc, it has a down stream O2 sensor, the computer will try and try to compinsate and throw codes and run like crap.

Depending on what state you live in, it can be a bit of a fine to get caught without one.  In my town, I've seen random smog test checkpoints on the road.  Would hate to get busted at one of those.



It really depends what the motor is and what you want to do.  In California, you can avoid issues with emissions by registering as off-road use only, but it requires you to never drive it on normal highways.

[Bounty Hunter]

What year jeep you working on? 

Late-model converters aren't very restrictive, you don't stand to gain much unless the converter is plugged.

[sharpxmen]

On a 4cyc, it doesn't have a down stream O2 sensor, so it won't know or really matter.

On a 6cyc, it has a down stream O2 sensor, the computer will try and try to compinsate and throw codes and run like crap.

what does cyc stand for

he's got a '93 YJ, downstream O2 for cat efficiency was introduced on OBDII TJs as far as I know (not sure if that's what you meant but sounds like it, if you meant cylinders i don't think 4 or 6 made any difference as far as 1 or 2 O2 sensors)

[aka-justin]

what does cyc stand for

he's got a '93 YJ, downstream O2 for cat efficiency was introduced on OBDII TJs as far as I know (not sure if that's what you meant but sounds like it, if you meant cylinders i don't think 4 or 6 made any difference as far as 1 or 2 O2 sensors)

I meant cyclinder and my bad.

[Torch_Ind]

 downstream O2 for cat efficiency was introduced on OBDII TJs as far as I know

+1

as for pro and cons even in obII system the most it will do is throw a code.  and yes depending on state you could get charged for not having one

and your tail pipe will pollute more

[Jeffy]

What year jeep you working on? 

Late-model converters aren't very restrictive, you don't stand to gain much unless the converter is plugged.

This is true.

[Torch_Ind]

This is true.

+1

only people that think removing the cat gives you horsepower is the people who think more noise = power witch isn't always the case

[dwtaylorpdx]

I've been checked in more than one state for emissions roadside,
(Way back delivered construction equipment around the west)
CA used to do random group pullovers and use mirrors to look
under cars, Nebraska too. What sucks is if they catch you and
just feel like being jerks they can take your vehicle and impound it,
then make it a ^%$% to get it back.... Costa lots of money....Bad thing (TM)

Dave

[lqdtrance]

Wow, so many reply's already. I have a 1993 YJ 4cyl. I had always heard about power gains from not having it hence the question. I actually do not want a loud vehicle at all. Good info and thank you. I think mine may be clogged a little. I'm looking into replacing it. Adding it to the list.

[Jeffy]

Wow, so many reply's already. I have a 1993 YJ 4cyl. I had always heard about power gains from not having it hence the question. I actually do not want a loud vehicle at all. Good info and thank you. I think mine may be clogged a little. I'm looking into replacing it. Adding it to the list.

If you get a CarSound by MangaFlow ($100), it will be bolt-on.  Well once you get the cat off the muffler.  Otherwise replace the whole exhaust with a cat-back and bolt it on.  Makes for easing tweaking and fixing.

[cz777]

with obd 2 ,you find a 02 simulator for the other side of the cat ......one thing about cats they get very messy with rare geses worst then normal combustion  not mention the corrosive gases also back pressures !!! 

[Torch_Ind]

with obd 2 ,you find a 02 simulator for the other side of the cat ......one thing about cats they get very messy with rare geses worst then normal combustion  not mention the corrosive gases also back pressures !!!  

what are you talking about?

cat's take hc, co, NOx and convert "hints converter" to H2O "witch is water vapor state" and CO2

how is that rare gasses? converters are better for the environment. thats the only reason they are in the exhaust!! clean up pollution. with a proper flowing cat there is no power loss!!  the reason for the larger piping at the cat section is to = the same size pipe with the added materials in it!!.

only thing your doing not running a cat is polluting "witch some states you can get charged for"  slight noise reduction due to sound waves bouncing around in the materials in the cat!  and one other benefit is cash in your pocket from not replacing it "if you don't get caught without one" 

[Jeffy]

The only toxic part about the cat is the heavy metals used in the catalyst.  You do not want to breath them in.  The catalyst converts the harmful gasses into more inert gases and or liquids.

Another thing,  some places will pay you for your old catalyst.  Usually $50-100 depending on the size.  I didn't bother doing that with mine but if you want to spend even less then look into recycling your cat.  That is if the catalyst is still in the can.

Oh another negative of not running a cat is that your exhaust will smell even worse then normal.  On a trail, I'd hate to be the guy running behind you.

[Torch_Ind]

The only toxic part about the cat is the heavy metals used in the catalyst.  You do not want to breath them in.  The catalyst converts the harmful gasses into more inert gases and or liquids.

Another thing,  some places will pay you for your old catalyst.  Usually $50-100 depending on the size.  I didn't bother doing that with mine but if you want to spend even less then look into recycling your cat.  That is if the catalyst is still in the can.

Oh another negative of not running a cat is that your exhaust will smell even worse then normal.  On a trail, I'd hate to be the guy running behind you.

+1 any metal yard will usually take a old cat.

+1 on the smell