Cats or no?

[13JBecker]

Hey there guys my name is Justice and I'm a new member here. I just bought a 99 2 door Tahoe, LT, loaded with options, 4x4. It's a great looking truck and I'll soon be putting an exhaust system on it. For the sake of saving money, it will be true dual straight pipes from the cats back. If I don't like the sound, I'll put mufflers in later when I have the money. My question is however, should I replace the cats with pipes and o2 simulators or just leave them? I initially thought I should leave them so I don't have check engine lights. But I've heard straight piping a vehicle can cause the cats to fail earlier and I should just lose them now instead of later. Thoughts?

 

[Jerky Arm Ape]

The cat-back straights with 4x18" tips is my most favorite exhaust system on the Tahoe & Yukons.
It's the deepest loud exhaust there is.
I used several different tip sizes to find the sweet spot.

It is more unhealthy for the catalytic converters.
But if you don't over do it and use the same size pipe on the back side (2.25") then you will get a decent service life out of your converters.

 

[Gzes]

Itl be fine later down the line you can get some high flows

 

[SunlitComet]

I am sorry, what is unhealthy for the cats?

 

[Goodinblack]

I am sorry, what is unhealthy for the cats?

 

[Jerky Arm Ape]

I am sorry, what is unhealthy for the cats?

That really cheap "crunch food" that doesn't have a known name brand.

 

[SunlitComet]

Uh ha ha. I was referring to the piping issues you were discussing.

 

[Jerky Arm Ape]

More or less what i posted is in theory, not really an issue.

If you use larger pipe after the converter then the exhaust flow will expand before it moves rearward to exit the tailpipe, therefore, lessening the back pressure even more than it would if you use the same size pipe on each side of the converter.

This is a discussion that could run on forever.
Like I said its more In theory than anything else.
Wrong or right it's something to chew on.

 

[SunlitComet]

Lets end that discussion right now. Doing that does not hurt a converter. Having contaminants in the exhaust or the wrong A/F ratio does.

 

[Jerky Arm Ape]

Lets end that discussion right now. Doing that does not hurt a converter. Having contaminants in the exhaust or the wrong A/F ratio does.

So if you don't say it it isn't right huh sunlitcomet ?

Very easy concept to grap.

Increasing the flow allows some of the heat that is usually absorbed by the manifolds to make its way to the converters.

The stock manifolds are made of very thick metal and takes time to disparate and absorb the heat which will now flow through the converters making the internals hotter.
Which will lessen the "life span"



Hence forwarth the need for "headers" made from thinwall tubing.

Adding flow to an engine needs to be a balanced process.

GM designed the system to work together.

When you change one thing, there is other components of the system to consider.

Again what I'm describing is very tedious and not recognized by many.
As in.... Well you aren't going to listen anyway.

You'll just say I'm wrong again, right?


Again mostly in theory no factual information, though if you have the ability to understand and accept logistics then you can grasp the concept.

'Nuff said