04Tahoe LT headers with stock y-pipe & cats?

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BossGunner

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Hello first time posting so forgive me if I miss something here. I got a pair of pacesetter LT ceramic headers on a screaming deal and want to try to keep my stock y-pipe and cats. I've heard of this being done but I would like to ask this forum for potential thoughts. Right now my rig is a stock 04 tahoe 4x4 with a 5.3 v8. I'm worried about if I go catless about the future drivability of it, since it's my daily driver. That and I dont exactly have the dough to go and get a tune if I go catless. Thoughts? Any help is appreciated.
 

iamdub

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The LTs extend past where the factory Y-pipe and cats are located. You'd need a custom Y-pipe and have your factory cats reinstalled into that, just past the collectors, if that'll even fit. Otherwise, you'll have to get new, smaller aftermarket cats and hope they're sufficient.

You can't have the cats located too far downstream because they rely on reaching and sustaining certain temps to perform as intended. If not, they'll clog up.
 
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BossGunner

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The LTs extend past where the factory Y-pipe and cats are located. You'd need a custom Y-pipe and have your factory cats reinstalled into that, just past the collectors, if that'll even fit. Otherwise, you'll have to get new, smaller aftermarket cats and hope they're sufficient.

You can't have the cats located too far downstream because they rely on reaching and sustaining certain temps to perform as intended. If not, they'll clog up.
If I were to have room how far down would be too far? is it just a guessing game if it's not the stock location? If i were to go catless how bad would it be if i didn't get it tuned right away and how horrible will the gas smell? i know to expect some smell as the cats wont be burning the excess anymore but I'm trying to get an idea of what it'll be like.
 

iamdub

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If I were to have room how far down would be too far? is it just a guessing game if it's not the stock location? If i were to go catless how bad would it be if i didn't get it tuned right away and how horrible will the gas smell? i know to expect some smell as the cats wont be burning the excess anymore but I'm trying to get an idea of what it'll be like.

It's a temperature thing, so however far down the line where the exhaust is still at least 500° would work.

I deleted my cats when I got headers. The sound (note, not volume) is the only part I like about them being gone. Other than that, catless kinda sucks, IMO. The exhaust volume is so much louder and the smell is thick and nauseating. You can't idle or drive with the windows down as the currents seem to suck the fumes forward. Seriously, the exhaust seems to defy physics just to get inside your car and soak into your clothes and interior. You have to wait until everyone is in the car with the doors closed before starting it. I mention this because I'm outnumbered by females in my household. When we're all about to go somewhere, they all realize at the last second the things they forgot and have to go back in the house. Once they've finally gotten all their stuff, then they all gotta get back out to go pee. Sometimes there's an emergency makeup fix. Every time they get out to run back in, they leave the doors open and the fumes flood the cabin. This BS has long been remedied, but I wanted to mention it to reinforce just how much of a nuisance going catless can be since you have to alter your life to accommodate it.

After losing the cats, it took 40" of muffler to quiet it back down to where I like it. Before, a simple 18" straight-through muffler was perfect. I have some Magnaflow cats that I'm considering installing into my Y-pipe.

All the tune would do, as far as the deleted cats, is turn off the catalyst inefficiency codes. You might be able to have the idle tune adjusted to run lean or whatever to reduce the smell when idling. But, all other instances still apply.
 

Tonyrodz

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It's a temperature thing, so however far down the line where the exhaust is still at least 500° would work.

I deleted my cats when I got headers. The sound (note, not volume) is the only part I like about them being gone. Other than that, catless kinda sucks, IMO. The exhaust volume is so much louder and the smell is thick and nauseating. You can't idle or drive with the windows down as the currents seem to suck the fumes forward. Seriously, the exhaust seems to defy physics just to get inside your car and soak into your clothes and interior. You have to wait until everyone is in the car with the doors closed before starting it. I mention this because I'm outnumbered by females in my household. When we're all about to go somewhere, they all realize at the last second the things they forgot and have to go back in the house. Once they've finally gotten all their stuff, then they all gotta get back out to go pee. Sometimes there's an emergency makeup fix. Every time they get out to run back in, they leave the doors open and the fumes flood the cabin. This BS has long been remedied, but I wanted to mention it to reinforce just how much of a nuisance going catless can be since you have to alter your life to accommodate it.

After losing the cats, it took 40" of muffler to quiet it back down to where I like it. Before, a simple 18" straight-through muffler was perfect. I have some Magnaflow cats that I'm considering installing into my Y-pipe.

All the tune would do, as far as the deleted cats, is turn off the catalyst inefficiency codes. You might be able to have the idle tune adjusted to run lean or whatever to reduce the smell when idling. But, all other instances still apply.
I agree on the noise and fume issues. I'm running long tubes with no cats also.
 
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BossGunner

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Hmm well damn. I'll talk with my shop and see what they can do about repositioning the cats with the LTs. If/when I can get it done I'll update with photos and statuses. Wish me luck. Worst case, I'll keep the tubes and the truck as a future project toy when I might get a newer more fuel efficient daily.
 

Tonyrodz

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Hmm well damn. I'll talk with my shop and see what they can do about repositioning the cats with the LTs. If/when I can get it done I'll update with photos and statuses. Wish me luck. Worst case, I'll keep the tubes and the truck as a future project toy when I might get a newer more fuel efficient daily.
Shouldn't be a difficult job for a competent shop.
 

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