catilytic converter question

[west chevy hd]

i have a 2001 chevy tahoe and one of the catilytic converters is making some noise so i know its bad. hears my question. i dont want to by the whole duel oem cat converter i just want to replace the one thats bad... can i just buy a single universal cat, cut the bad one out and weld it? has anyone done this or are the bends in the exhaust to extrem for a universal to fit there?

[PeterbiltChrome]

if they're bad won't the o2 sensors let you know? pull codes? does your exhaust smell like it's overfuelled?

 

as for the noise, check the heat shield on the cat or starter heat shroud... check bolts on collector fittings too...

[west chevy hd]

it sounds like the baffles are broken up in there. ive checked everything else. can you have busted up baffles and not throw codes?

[Bluesman123]

Your 2001 OBD-II system monitors the O2 level before and after the cats. If the difference falls outside a predeterined range you will get a check engine light and a code. If you've just run extra rich for some reason you may have cracked loose some of the honeycomb, but it may not be enough to be detected as a bad cat. Really, check out things like that sheet-metal heat shield first.

 

I can't tell where you live, but if you end up replacing the cat you had better not live in California...or if you do you better be sitting down. The last time I checked (last fall) there were no approved aftermarket cats for GM OBD-II trucks. With my mechanics discount, an AC Delco cat (just 1, my man) cost about $500. If you don't live in California there are aftermarket cats and they cost about half that, more or less.

 

Of course if you don't live i California you don't get automatic phone calls from your governator asking you to vote for his measures. Its a special kind of thrill to hear the terminator's voice asking you to do something!!!

 

Dave