what is the stock layout for 95 k2500 sub 4x4?

[japhethlarge5280]

My truck wont smog cuz it has been modified with catback exhaust...the smog guy insisted that cat must go behind muffler toward rear..in order to pass smog.....but i look online and the cat is never behind the muffler...what is the stock layout for 95 k2500 sub 4x4?

 

[Mangonesailor]

My truck wont smog cuz it has been modified with catback exhaust...the smog guy insisted that cat must go behind muffler toward rear..in order to pass smog.....but i look online and the cat is never behind the muffler...what is the stock layout for 95 k2500 sub 4x4?

Guy doesn't know what he's talking about, or is playing you for a fool. Take it elsewhere.

In every single vehicle i've ever owned, or seen, i've never seen a cat behind a muffler.

 

[df2x4]

Guy doesn't know what he's talking about, or is playing you for a fool. Take it elsewhere.

In every single vehicle i've ever owned, or seen, i've never seen a cat behind a muffler.

X2. That's ridiculous.

 

[RichLo]

The cat needs to get heated up to work right, it needs to be as close to the manifolds as possible. He might be trying to sell you a bigger more expensive cat to pass emissions.

 

[Mangonesailor]

The cat needs to get heated up to work right, it needs to be as close to the manifolds as possible. He might be trying to sell you a bigger more expensive cat to pass emissions.

It sounds like he's trying to charge him for labor, but the way OP sounds he thought he could get by with it.

 

[someotherguy]

For clarification: not ridiculous. Incorrect for his application, but not incorrect in general. There are more than a few factory setups with the cat behind the muffler. Don't ask me why; I don't know. But it exists, and I've seen it. A GMT400 example: my 1995 3500HD had stock exhaust and the muffler is ahead of the cat. This is also on a manual-trans equipped truck with a one-wire (non-heated) O2 sensor. Of course, emissions standards are more lax on higher GVWR vehicles, at least back then, so go figure.*

Back to OP's truck, cat comes before the muffler in THAT application. Your stock exhaust (some of which sounds like it's still intact) is each manifold connects to a Y-pipe, Y-pipe has a cat bolted to it at a flange, and the muffler is behind the cat.

* Sidebar interesting story; a 3500HD although being 15,000 lb GVWR is listed on the title as "1 ton" so they tested it against 1 ton standards - 10,000 lb GVWR shown on the test sheet. It passed beautifully, especially for a 281K mile TBI 454 with what appeared to be the original cat on it.

Richard

 

[jrollings]

SOOOO glad I don't have to put up with that smog BS... it does sound like the guy is the typical theif-chian that makes us all look back instead of being a true honest technician

 

[japhethlarge5280]

Ok...my k2500 is indeed supposed to have a cat in back of the ****...thats how they made it stock..its been verified...BUT..I WENT TO A DIFFERENT SMOG SHOP...and passed no prob...he overlooked the cat location ..probably cuz its so rare...anyway...now i dont have to cut up my exhaust system and piece together...thanks guys for all the help

 

[df2x4]

For clarification: not ridiculous. Incorrect for his application, but not incorrect in general. There are more than a few factory setups with the cat behind the muffler. Don't ask me why; I don't know. But it exists, and I've seen it. A GMT400 example: my 1995 3500HD had stock exhaust and the muffler is ahead of the cat. This is also on a manual-trans equipped truck with a one-wire (non-heated) O2 sensor. Of course, emissions standards are more lax on higher GVWR vehicles, at least back then, so go figure.*

Back to OP's truck, cat comes before the muffler in THAT application. Your stock exhaust (some of which sounds like it's still intact) is each manifold connects to a Y-pipe, Y-pipe has a cat bolted to it at a flange, and the muffler is behind the cat.

* Sidebar interesting story; a 3500HD although being 15,000 lb GVWR is listed on the title as "1 ton" so they tested it against 1 ton standards - 10,000 lb GVWR shown on the test sheet. It passed beautifully, especially for a 281K mile TBI 454 with what appeared to be the original cat on it.

Richard

I swear I learn something new every day on here.

 

[someotherguy]

Ok...my k2500 is indeed supposed to have a cat in back of the ****...thats how they made it stock..its been verified...BUT..I WENT TO A DIFFERENT SMOG SHOP...and passed no prob...he overlooked the cat location ..probably cuz its so rare...anyway...now i dont have to cut up my exhaust system and piece together...thanks guys for all the help

Cool; wasn't sure on the 2500 Suburban, most everything I've seen lighter than a 3500HD had the normal cat-then-muffler arrangement. Glad you got it handled though.

Most of the smog inspector type guys have a binder they can look through for that kind of info. Really surprised me to see the inspector here open it up and point to an f'in picture of the heat riser flex-tube that my '94 Suburban C1500 was supposed to have, and he FAILED me for it.

Richard