runnin rough

i got a 98 blazer, its runnin a lil rough, it sound like it has a damn V8, and shakes real bad, but its a stock 4.3 V6, its sounding real throaty, maybe tha Cat. converter is clogged? anybody got ideas, and how much itd cost to replace it

when was the last time you put plugs in it man? i had this problem in the same style blazer once it turned out to be the last plug on the driver side kinda hard to get to unless you remove the driver side whee and tire.but it ran like that rough idle and whatknot?? i dodno just my experiance

yea i forgot to mention that, i was told 2 and 5 plugs werent firing, i said fuck it and changed all 6, and its still doin it, could a vaccum hose be doing it? cuz i hear a hissing comin from under tha hood

check your distributor cap and rotor and plug wires

ok, so far ive changed, spark plugs, s.p. wires, dist cap, and rotor!!!! what else? messed up valve? im runnin outta ideas and need this to run yester day!!

it sounds as though i have a vaccum leak, could this cause it to bog down? how can i find it, i can hear that sumbitch, but i cant tell where its coming from

I dont know about on a chevy but I had a honda accord that had a vaccum line from the intake that came loose once in a while and caused it to run like shit and bog down.

see thats where i keep hearing it come from, but cant find that sumbitch, how can i find it?!

this will sound funny but check out the vacum on the heater.i put my dash back in and a leaking vacum line on the hear was fucking shit up.sounded like it was comeing from under the hood but it wasent.thats bought all my thoughts with out being there man.if not that find yourself a chiltons book for it and just trace all the vacum lines useing the diagram or you truck may have a diagram uner the hood?

soit shouldnt be a valve, or a clogged cattilic converter?