tomz240

I am putting LT headers on my 02 Vette. I live in a county that requires emissions testing. I've been told if after installing the headers and get a dyno tune the tuner can deactivate the rear o2 sensors and the emissions test machine will not notice and will pass it. Before I install headers without cats I like confirmation this is accurate.

Thanks guys.

02torchred

Does yours do the sniffer test or diagnostic? If the former, then I don't think it will work. The carbon monoxide will be plentiful. I've never lived in a state with emissions testing though, so I can't really be much help there.

Also, have you ever owned a car without cats?

On my last car, I removed them and had them back on in a month. Anytime I drove it, or was even around the car with it running ie. walking behind it, showing friends, etc. my shirt would literally smell like gasoline. It would linger, and be on me. Not to mention just smelling it in general from the car. In the end I just didn't think it was worth the arguable 5hp.

tomz240

The way I see it is I can always add cats later if it doesn’t work out. Anyone see any reason why that wouldn’t be a good idea?

wscott62893

My opinion is go for it! You won’t know if you love it or hate it until you drive without them for a while. I have 1-7/8 LTs with 3” catless X pipe and Corsa Xtreme. It’s loud, smelly, and amazing...but I don’t DD my Vette and am a purist. So I love the raw nature of a cat less setup.

I live in an emissions state (PA) and would certainly fail a sniffer test, which is required in PA. My strategy, drive less then 5000 miles a year so I am exempt from any emissions testing. Small beneficial loop hole here in PA. If I go over 5k miles...I know a guy...but don’t expect to have to exercise that hookup.

449er

There is no sense in running a system without cats, not only is this not a environment friendly idea, but you gain virtually zero hp & your car will stink like rotten eggs. The headers will give you plenty of sound if that's what you are shooting for

tomz240

Actually there is a benefit. $500 savings not having to buy cats. Plus the cats I have to use with my system in order to keep modifications to a minimum have been on backorder for 8 weeks now. . I only drive the car around 3k per year, so I doubt my contribution to the destruction of the earth is significant.

wscott62893

Be honest...you daily drive a Prius don't you...

Sorry, I'm sarcastic before my morning coffee. Everyone is entitled to an opinion! I guess I like being smelly

Fastbird

To directly answer your question, if it's is a "Scan Only" emissions test, then yes, if the rear O2's have been turned off thus disabling the CEL for them, you will pass. If however, a tailpipe sniffer is used (unlikely, I only know of these being used on Pre OBDII cars), you'll fail because of the lack of the cats.

tomz240

Car is a 2002. No sniff test I’m aware of.

449er

I actually drive a Silverado as my dd & this is my weekend 7 liter "Prius"

wscott62893

That's my kind of Prius nice!

bravo29

Plus depends on what type of exhaust you have. Your car will be LOUD.

All my friends who don't have CATS I can hear them coming blocks away when coming over.

They all stink like rotten eggs on long drives.

tomz240

Corsa Extremes

RockyMtC5

I have no cats on my h/c supercharged C5 and my 2004 Jeep Rubicon and although you can smell the raw gas it does not smell like rotten eggs, ever. Not sure where anyone came up with that!

tomz240

Someone with flatulence issues I suspect.

wscott62893

Rotten eggs is typically the smell associated with exhaust smell when your cats are cold and not working efficiently yet...not sure why people think it’s the smell you get without them. Like you said, it’s the gas smell you get without cats. So having no cats actually smells better then with cats

02torchred

$500 extra? I'd recommend to just get the JBA headers, they come stainless steel, ceramic coated, or titanium coated. $650 ish although I've seen sales for much cheaper.

These come with flanges that mount to stock cats with minor cutting and welding.

In fact, these were the same used on superchevy.com a few years back and is still on their site today.

After going catless, it never made sense to me why people do it.

tomz240

I thought stock cats were restrictive.

wscott62893

To go catless or not has always felt like a “what’s the best brand oil” kind of thread to me. You’ll get 825 different opinions with a few facts mixed in. All the facts have been posted, in my opinion. The OP has the info they need to make a decision. Good luck with your choice!

Of course catless is the best choice

Beer:30

If there is a visual inspection I would expect you to fail. No cats is kind of obvious.
I would say you have a choice where you can either pay to put them on now or pay even more to have them put on later.
You get to pick!