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Discussion Starter #1
Hey ya'll, i just removed my catalytic converter pipe. from feedback from you, i believe it may be plugged up. i have gutted the second canister (i pulled out all the honeycomb, a couple mesh sections, and what looked like steel rope or something. what is the first canister where the two pipes off the manifold meet up? is it another cat? or just a resonator? is it prone to plugging up?
thanks in advance.

Pete
 

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Crusher Mike
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you have a primary and a secondary. In AZ you will not pass emissions with one unless you have a high flow which acts as two but you have better flow.
 

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Discussion Starter #3
i'm in florida, where they don't even do inspections, i would kinda like to cheapo the whole thing, i guess i could cut it on the backside. at least then i could gut that one, and then only have to have 1 pipe welded?
 

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green ones make me horny
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if you want to go cheap just eleminate your cats period and put a pipe all the way to your muffler. that is what i am going to do when i wquit being lazy.

ken
 

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imlikeojnow said:
if you want to go cheap just eleminate your cats period and put a pipe all the way to your muffler. that is what i am going to do when i wquit being lazy.

ken

This is exactly what I want to do. I have been concerned about it affecting the computer, sensors, blah blah blah. Will this work with no downside?
 

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Discussion Starter #7
egr pipe?

what do you do with the egr supply pipe? doesn't it need to provide exhaust to the thermactor too? i gutted both canisters and now i'm gonna get a buddy to weld the pipe back together. if you cut it right behind the first cat, it's pretty round, and a straight shot. does anybody think this will cause any backpressure issues?
 

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Satyr of the Midwest
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The EGR tube has nothing to do with the catalysts, nor the Thermactor system(s). Leave the EGR tube alone, and make sure it's intact, or you'll be sucking raw air into the intake manifold. Been there, done that, not cool. Also, make sure that your Thermactor pipes have a home. Otherwise you'll get backfiring and a screwed-up signal from the HEGO, and aren't cool either.

The only backpressure issue you'll have is a $hitload LESS. Which is a good thing. :D

Paul: it won't do any harm to the way the EEC does its thing. The only FSB's that would are 1996 models or those with OBD-II, because they have HEGO's after the catalyst to make sure it's working. You can use a plug-in module on those years to fool the computer, however on your 1991 model this isn't a worry. I see in your profile that you've already disconnected the air pump, so it's very possible you already have a clogged cat. BTW, you ready for the 'big snow'? :D

FYI, we used to call it "rodding the cat" when punching the catalyst beds out with a piece of concrete re-bar. Works well, looks stock, and makes the shell act as a resonator. God I love Michigan....but for this reason only...lol.
 

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green ones make me horny
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Paul91 said:
This is exactly what I want to do. I have been concerned about it affecting the computer, sensors, blah blah blah. Will this work with no downside?

dont see how it would effect anything your o2 sensor is in your y pipe so no biggie thgere.
 

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Thanks for the response Sig and im. Ugghhhh more snow, the reason I need to live in the Carolinas. I am so sick of winter. Thanks again.
 

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Most had a dual cat system, its a 2 stage system. You can replace both with a single that does both stages in one cat. It doesht *have* to be a high-flo, but it wouldn hurt... you can just swap with a generic replacement. HTH
 

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Discussion Starter #13
results

well, i had the two cat pipes welded back together, and re-installed it. i hung a cheap thrush turbo muffler on it with a turn down. sounds pretty good, very deep, but raspy up top. unfortunately, the truck is still missing between 1500-1800 rpm. the search continues.

Pete
 
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