Gutting cats/o2 sims questions
05-05-2004, 05:21 PM
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Gutting cats/o2 sims questions
How do you gut your cats(do you unbolt from the exhaust manifolds and ram a pipe throught themtill there is no resistance left?) Also will it mess up emmissions? How much and how hard are o2 sims to put in? Ant tunning needed with them? Any vids with truck with gutted cats?
05-05-2004, 05:53 PM
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I heard you just hollow them out and need to buy new o2 sims and those just plug in i think and it messes with emmisions but i think you can get away with you just need every thing done right i know i am gona do it to my truck because there is like 15 hp stuck there so they must go
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yellow 4.8 flowmaster and hypertech
05-05-2004, 08:50 PM
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the old type had what looked like fireproof cat litter in them and were really contrictive. not sure if the newer [round] are the same or the screen type. i put a high flow screen type on my bronco ,seemed to help. i was told the stocks on the 02 flow pretty good until you get alot of miles on them, also found out you can't legally change them in ca. until you have 50,000 on your truck. o2 sims just plug in, or if you have edit you can just turn them off. i have set for an o2, if you have the same plugs, they should work, i'll sell them cheap. if not caspers electronics sells them. i'll look for the phone number tonight.
05-05-2004, 10:34 PM
#6
it would be hard to do without cuting the y pipe somewhere.
most people say about 5hp is all they are worth but that is 5 free hp so why not.
you emisions will definately be messed up, if there is any kind of testing in your area you shouldn't do it.
if you plan on going very far with your truck i would skip the simms and get edit. right off the bat you can turn off those o2's so no ses lights, and another nice thing you can do is shut off "cot" or cat over temp feature, that is reportadly good for 10hp in some parts of your rpm range. then there is all the other stuff you can do with edit like up your shift points and add a little timing and adjust the fueling if you want.
most people say about 5hp is all they are worth but that is 5 free hp so why not.
you emisions will definately be messed up, if there is any kind of testing in your area you shouldn't do it.
if you plan on going very far with your truck i would skip the simms and get edit. right off the bat you can turn off those o2's so no ses lights, and another nice thing you can do is shut off "cot" or cat over temp feature, that is reportadly good for 10hp in some parts of your rpm range. then there is all the other stuff you can do with edit like up your shift points and add a little timing and adjust the fueling if you want.
05-06-2004, 01:54 AM
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I say dont bother with the hassle...spend the 190 on the offroad ypipe from gmpartsdirect so you have the original with cats to bolt back for emissions.
not to menton the flow would be better then just gutted cats as that would add alot of turbulance.
not to menton the flow would be better then just gutted cats as that would add alot of turbulance.
Originally Posted by parish8
it would be hard to do without cuting the y pipe somewhere.
most people say about 5hp is all they are worth but that is 5 free hp so why not.
you emisions will definately be messed up, if there is any kind of testing in your area you shouldn't do it.
if you plan on going very far with your truck i would skip the simms and get edit. right off the bat you can turn off those o2's so no ses lights, and another nice thing you can do is shut off "cot" or cat over temp feature, that is reportadly good for 10hp in some parts of your rpm range. then there is all the other stuff you can do with edit like up your shift points and add a little timing and adjust the fueling if you want.
most people say about 5hp is all they are worth but that is 5 free hp so why not.
you emisions will definately be messed up, if there is any kind of testing in your area you shouldn't do it.
if you plan on going very far with your truck i would skip the simms and get edit. right off the bat you can turn off those o2's so no ses lights, and another nice thing you can do is shut off "cot" or cat over temp feature, that is reportadly good for 10hp in some parts of your rpm range. then there is all the other stuff you can do with edit like up your shift points and add a little timing and adjust the fueling if you want.
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05-06-2004, 02:53 AM
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i'll go both ways on that, cause i've spent alot of time doing "free" mods on every vehicle i've ever owned. if i paid myself $5 an hour for those free mods, i probably could have bought a new truck. if it's only 5 hp ??? seems like alot of effort. if you have more time than money, go for it. anything inside that cat would probably be considered toxic, don't breathe the dust.
05-06-2004, 05:05 AM
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Originally Posted by Visionxorb
I say dont bother with the hassle...spend the 190 on the offroad ypipe from gmpartsdirect so you have the original with cats to bolt back for emissions.
not to menton the flow would be better then just gutted cats as that would add alot of turbulance.
not to menton the flow would be better then just gutted cats as that would add alot of turbulance.
05-06-2004, 05:37 AM
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Check First.
If you have aftermarkets, better tap them with a wrench to listen if they are hollow. I purchased Random Technologies highest flowing CATS and within 3 months, the ceramic was blown out of them, anyway. It started when I bought the Y-pipe with high-flow CATS. I busted the right side ceramic during installation and finally, after 3 months, ordered a new CAT to replace the damaged one. I got the new one in the mail and it had no OS2 bung to screw the OS2 sensor into. RT said they would customize it for an ungodly price and that they don't make replacement ones. I had a welding shop to cut a hole and install a threaded bung to screw my OS2 sensor into the converter. When the shop took off the old one, it was hollow and we checked the left side. It was hollow as well .... and I was surprised. That was supposed to have been the GOOD one. So, just tap your coverters with a wrench and you can clearly tell if they are hollow. If you hear a firm peck, they're intact. If you hear a resounding 'ding' they're already hollow and you don't need to waste your time removing them. Hope this helps you.