Going catless for beginners

[Beginner]

Hi guys I'm looking to go catless on my 08 1500 with the 5.7 hemi I have a k&n cold air intake and diablosport trinity, I don't mind a check engine light but do not want my truck to run bad or loose performance or mpg this is my newish car alwase had carberated motors so I'm looking for some advice on we're to start on this if anyone can help

 

[MegaMouseGW]

First some states are rather **** about cats. I would check the local laws before you remove them. Mouse was wrong to post what he did.

 

[truckin151]

Check your emission laws first, that's a nice fine if caught without them. second is you might feel a hit to your lowend. With little done to the truck it can feel like it's falling on its falling on its face without them.

 

[truckin151]

Do not destroy them either wait until you know that you don't need them and how your truck runs without them. They are expensive to replace and if you go oem they are hard to find.

 

[MegaMouseGW]

Truckin151 is right. Check the local emisions laws first. Some states check for the cats and if they are missing you will fail the inspection. New cats are not cheap so disregard my earlier suggestion completely. From what I have read up on the 5.7 needs the back pressure that the cats provide to run properly or it does just as Truckin151 says and falls flat on its face.

 

[ATXHEMI]

And it stinks real bad. I can't wait to get my hiflows put on.

 

[TylerB]

Love that smell

 

[joeg45]

I would say go high flow or if you really want no cats get some resonators that are roughly the same size so you won't fail visual inspection ( go to a shop that kind gives it a quick look) that's how one of my buddies does it but that's in texas

 

[ST-8]

Glad we don't have to deal with emissions stuff in FL. An IMO I too love that smell the exhaust gives off w/o cats. An I didn't notice low end loss when i ditched cats but did a full exhaust when I got rid of them

 

[Beginner]

Thanks for the quick responses,I'm here in Oklahoma and have never had any of my vehicles checked before so don't think we have those emissions laws so I think I good on that part and was planning on keepin the cat in my barn just incase tere was a power loss
A buddy of mine told me about a spark plug non fowler trick to move the 02 away to make it run normal but I have not idea about any of this stuff like I said iv alwase had carberated so I don't know the first thing about these but thanks for all your help in advance

 

[truckin151]

Also the cats don't bolt on and off, you have to physically cut them off and weld or clamp in a straight section. Best thing would be to try it and see how it does. I know plenty of people that have done it with no issues although most of them had more to bump up the lowend, and plenty of people that have had issues of it falling flat. For the 5 extra hp, on an already high flowing cat, it wasn't worth it to me to keep it like that.

Try it, if it works for you, you don't get any lowend loss, you can stand the increase in the unrefined exhaust note and don't mind the smell of unburned hydrocarbons keep them off or modify them.

 

[WhiteExpress]

There is no 'Check Local Laws' people!

A catalytic converter is part of a federally mandated emissions system.
Intentional removal of this unit can be subject to hefty fines.
(upwards of 10k for first time offenders!)

Local laws don't matter if you're breaking a federal regulation. A modern high flow catalytic has very minimal impact on a daily driver as is. Sure, they might cost you 5-8HP at top end, but does that really matter in the real world?

You tell me.

 

[redram2007]

Here's some reading material.

Bear River Converters Forum - What is a performance catalytic converter

 

[WhiteExpress]

Here's some reading material.

Bear River Converters Forum - What is a performance catalytic converter

This was very informative about the construction of catalytics!

Thanks for the post good sir!

 

[dodge dude94]

Here's some reading material.

Bear River Converters Forum - What is a performance catalytic converter

OMG.
Just from reading that thread, I have a high flow cat on my truck.

I don't think I have the 400dpi insert, pretty sure I've got a 200dpi insert

Good beans.

*edit*
Disregard, just went through my pictures. 400dpi insert.
Damnit.

 

[emjohn4]

There is no 'Check Local Laws' people!

A catalytic converter is part of a federally mandated emissions system.
Intentional removal of this unit can be subject to hefty fines.
(upwards of 10k for first time offenders!)

Local laws don't matter if you're breaking a federal regulation. A modern high flow catalytic has very minimal impact on a daily driver as is. Sure, they might cost you 5-8HP at top end, but does that really matter in the real world?

You tell me.

Exactly.

I don't know what people think are in a catalytic converter - I swear some think there must be a steel plate with only a 1/4" hole for flow, and removing them is the equivalent of pulling the plug in a seriously full bathtub!

Go ahead and pull them off. You will likely never get caught, unless you have emissions testing. But, you'll not likely see any gain, and you will get a stinky exhaust. Any "gain" you swear you feel will be purely mental.

Realize that it's a pretty pointless effort at any "reasonable" power level that you'll have in your truck.

 

[MegaMouseGW]

Here's some reading material.

Bear River Converters Forum - What is a performance catalytic converter

Great read. I stand corrected on my idiocy.

 

[truckin151]

IF you want to run no cats for what ever reason one has, CHECK the local laws.

YES it is a federal mandated emission control device, technically it's illegal through touch them, move them from their original location, or have a shop remove and replace them with a different one unless the cat is not functioning.

That being said, if your state does NOT do anything to regulate emission control systems, they do not do an emission test by sniffer test or visual inspection then go for it. If you get caught you're screwed but chances are you won't....

If you want to go through everything that is federally illegal or state illegal that people do to their vehicles or do while driving we will be here all night, I mean it's not like anyone one on here drives 1mph over the speed limit, because that's illegal as well.

Catless isn't for me although I can get away with it here. But I sure as hell won't tell someone who wants every hp out of their vehicle as they can, who knows the consequences and has weighed the chances from doing something to their vehicle.

 

[Beginner]

I did not realize it was that bad I thought it was more of a state/local thing,
I realized these new cats flow better did not know they changed to a different design from the pallet kind I figured 5hp gain but I Manley wanted the sound of a straight pipe all the way through without loosin power and mpg, and could someone explane to me why it would smell bad?

 

[truckin151]

Unburned hydrocarbons in the exhaust smell.