I have a 1979 Olds 350 Vin code "R" Federal 49 state car with 800 CFM quadrajet.

I live in California and need to smog this car every 2 years.

I have had the carb rebuilt, all new ignition, new EGR, New cataylic converter checked all for vacuum leaks, operation, timing, all to stock specs, etc.

I seems I need to buy new Catalytic converter every 2 years to make it pass.


maximum Specs at Mph

15 Mph 139 HC 0.90 CO 913 NO

25 Mph 116 HC 0.76 CO 815 NO


Passed test measurements:

15 Mph 5 HC 0.00 CO 537 NO

25 Mph 16 HC 0.00 CO 715 NO



I think too much unburned fuel is being dumped into Catalytic converter and burning it out.

Ideas please and thanks!

after 50 mi.

 

How do your plugs read? Is it running rich?

It's equally (more?) likely that you're burning a little oil and that's fouling the converter. How's your oil consumption?

Also, it's unlikely that whatever converter you purchase today is as good of quality as the factory original, so it may simply not last as long.

 

I disagree with that. The stock converter was the crappy, restrictive pellet-style converter. Today's ceramic matrix converters are both more effective and less restrictive. Of course, if you keep buying Chinesium bargain basement converters every two years, that may be the problem. Consider quality like Walker. And yes, the likely answer is that something is fouling the converter.

 

Good point, Joe. I was referring to build quality of the converter; I forgot about the pellet thing.

I'm not familiar with the catalytic converter set-up of 1979. Did it include an AIR system? If so, the OP should verify that the pump, diverter valve, and check valves are working properly and that the air line to the converter is hooked up and not rusted out. Not giving the converter fresh air when it needs it could also affect its longevity.