i had the cat taken out of mine cause it was bad, mine has a flowmaster. its loud as hell, and in my opinion it sounds really good. but as far as power i didnt feel no real increase in it. oh and i also have a CAI

 

To midnight: I hacked mine off for the same reason. It was rattling and I didn't like the sound. Come to find out, half the honeycomb was still perfectly intact, no melting or burning. Oh well. I like the sound now with a whole straight exhaust, Glaspack.

 

In recent years most car companies have made their catalytic converters really efficient without sacraficing power like in the mid-70's. On most modern vehicles there isn't a HP difference from running the stock cat vs straight pipe vs hi-flow. I have a hard time counting a dyno testing result of "+2-5 HP" as a real gain since that could be a matter of the test vehicle simply had a stronger pull.

 

when you all took off your cat, how does it sound? i have the flowmaster one in and dual out, it gace it a low tone to it now with the cat on. but i have made mine look like a muscle extreme, fat wide tires in the rear 4" cowl hood , i like to make it look fast knowing its still a 4.3 , but i thought i can get a lil more sound without the cat with a flowmaster? has anyone use the cold ait kit like from ebay? to remove the air box and to put that cold air on witht he cone filter? can ayone tell me what gear is there rear of the 5 speed 2002 extreme blazer? thanks to all of you for the info i get..

 

Mine got louder after removing the cat. The ebay CAI is useless unless you fab up some sort or heat shield to isolate it from the engine and the heat it produces. Otherwise you'll just be pulling in hot air and be worse off than with the stock airbox. You can find out what ratio the rear end is by looking at the RPO sticker in the glovebox. Look for a code beginning with GU or GT. When u find it, google RPO decoder and plug in the 3 digit code.

 

first off, i do thank all you guys who been giving great info!!
i just got back into the chevy world, i still have two mustangs...lol . but i rley on my chevy for everyday travel... to funny to say..
i am still thinking to remove my cat, if i can find away to do this..
is there any other bolt on or tricks to give a lil more power to the 4.3? i do have a msd 6a left over from my cars, can i hook that up ? i dont know how the coils are with that booster thing next to it works? i did do the throttle plate removal,, and wow it did change it,, any more tricks? im not looking to have a power house blazer.. then i drop in a 350,, but who has time or cash right now to play that one,,lol.. but hey any tips on what you all have done ,i love to hear.. i did add them oldschool latter bars to my rear springs.. too funny i sawa s10 with them,, im like wow that looks so tough.. so i got a set, they are cheap, so i put on,, you do fell the change from the rear.. but has anyone installed them?? when i did bolt them on like it says to. it all so crimps down the springs.. is that right? well you all, thanks again,

 

well my friends, i got it done today. wow it sounds really good with that flowmaster muffler. i feel a small amount differnts in take off, but it sounds great..