Bad Cat? Help

Today, I tried to start my car and it started really rough...shakes and rattles. Had to keep my foot on the gas or it would die. After a while, took my foot of the gas and it died. I looked at my carb and there are fumes coming out of it. It has been doing this as of late. I waited around 30 minutes and it started after I kept the starter engaged longer than usual. Pump is good, spark is good.

So it started again, this time it ran only if I kept my foot on the gas until it warmed up, but it was still running rough. I can hear the exhaust just rattling and sputtering. Took my foot of the gas and it died.

Looked at my carb and again, fumes coming out of it.

Any ideas?

OK, it just occurred to me, I have never replaced the oxygen sensors. Since they are cheaper, I should probably start with that instead of replacing the cat. Not sure if the symptoms I described would also be caused by Oxygen sensors...never replaced them, so not sure how difficult they are to replace.

OK, I replaced the oxygen sensor and it starts right up. Will drive it like this for a while and see if it makes any improvements. To remove the sensor I used pb blaster, a 22 mm crow foot o2 sensor socket and a braker bar.

Sounds like your carb is sad to me.

After doing some research, I tested the air vent cut off diaphragm, it didn't hold any vacuum. So I glued the plunger and disconnected its vacuum line 8. Can't believe how my car runs now. It starts and I don't have to give it gas like before, acceleration increased dramatically. Will look for a good part to fix it correctly, but iuf you have a carb then test this valve, page 11-80 on the shop manual. Will monitor and see what happens.