What are some effects of a bad O2 sensor. I know that it will cause your car to run a little rich. What else? Just pulled mine out and it was chared black That probably why I was running rich. I am still having some problems with my carb though. I need to lower the idle. It idles at 1000 rpm in park. Its pretty easy to lower it right? The rpms also fluctuate a couple hundred rpms and it stuters a little bit when im at a stop. Im thinking I have a vacuum leak. I need to get a guage to find out.

Heres a pic of my O2

 

Yup, rich.

I'd suggest you get a book called "Rochester Carburetors" by Doug Roe, or the Haynes "Rochester Quadrajet" repair manual. Either will help you understand how the carb works and what to do to get it working right.

A good number of carb problems are fixed with an ignition tune-up.

 

Definitely Rich. Replacing the old sensor couldn't hurt either.

 

And while the sensor may be sooted and blackened by carbon, that may not be the fault of the sensor itself, but the sensor only showing the result of a rich condition.

As a general rule, if your sensor has more than 30-40,000 miles of use, it may need replacement for peak efficiency. That alone may not solve your problems, however.

Clean spark plugs, good wires, distributor cap and rotor, clean filters, a working PCV system, and correct carburetor adjustment can solve a lot of problems. Simply cleaning the carburetor and repairing damaged vacuum lines may solve some of your problems. If the carburetor hasn't been adjusted in the past, there may not be a need to adjust it much once it is cleaned. A good reference book for E4ME carburetors would be a good idea.

 

HP Books "Rochester Carburetors" by Doug Roe, or Haynes Techbook "Rochester Carburetor Manual" are both excellent resources. The E4ME is only a subsection in both of them, but it is all that's needed specifically for this carb.

But, the ignition is the first priority.