Does a cat like engine oil?

siume99 · January 7, 2002

Hypothetically speaking If you had a "young" 1990 245,000 mile GMC Suburban, that has had blue smoke on startup "as a result of old valve guides," what sort of shape would you expect the catalytic converter to be in? How durable is the cat? Will just one puff of the "blue puff of smoke" destroy it? Oil comsumption while running is "none."

siume99 · January 7, 2002

I understand that sulfur can poison a catalytic converter quickly (thus the reason you don't have cats on diesels)...how much is in non-synthetic motor oil?

Shaners · January 8, 2002

I don't think the blue smoke will hurt it... But I bet the 245,000 miles has taken it's toll. I'd say your catalytic converter is probably worn out!!! That's not a problem unless you have to pass an emissions test. If you don't have emission testing in your area, then I would take it off because it is probably getting restricted and/or brittle. If some pieces come loose and start to block your muffler, then your "burb" will run like crap!!!

GreenRado · January 8, 2002

I had exactly that happen several years ago with my Quad 4 w/ about 175K miles on it. Dang thing just up and fell apart inside and clogged the crap out of the exhaust system - no real warning either!

Agree w/ Shaners - might be better to replace it w/ aftermarket (if you need to pass emissions testing) or take it off before it really screws up your valves, etc.

I replaced one on my 95 Jimmy with an aftermarket version, and it was surprisingly in-expensive - sorry don't know what brand, however.

chevy4x4trucks · January 8, 2002

I replaced one on my 95 Jimmy with an aftermarket version, and it was surprisingly in-expensive - sorry don't know what brand, however.

JC Whitney sells some non-name brand cat back exhuasts. You may want to check out there site and see what they've got.

siume99 · January 8, 2002

Thanks guys, I'll have to tell my friend that. He's also looking for a "new" '90 or '91 4x4 Suburban without much rust. Do you have any suggestions on where to look? He's not in too much need of a new vehicle he has a backup car on beautiful clear days (he has a 96 Impala SS.....rain and salt will not touch it).