1995 Saturn "rich mixture"

I have a '95 Saturn SL2 with 230,000+ miles (I’m very proud). It has been a fantastically reliable car. However, when I accelerate quickly, and let off the gas, the engine hesitates, sputters, and will eventually stall, if I do not give it enough gas. The condition is very apparent when I have the A/C on. When I described the problem to a friend, I said that it acted like I was flooding the engine. I tried fuel injector cleaners, replaced the fuel line and filter, cleaned the throtle body, poured “sea foam” in the vaccuum line and nothing has changed. I bought a code reader, and it indicated a “rich mixture”. When I had the emissions test done, it had a high reading while in the “idle” mode. My thought is that there is a bad fuel injector. Could there be some other problem that I am overlooking

It COULD be a leaking injector(s) allowing fuel into the engine in an uncontrolled manner. Stop shooting in the dark and have a pro check it out. It COULD be many other things…

For a rich mixture, these are the things to check.

A thermostat that is stuck partially/fully open.

A coolant temp sensor for the computer sending an incorrect signal.

A leaking fuel pressure regulator.

Tester

How about a recap as far as filters and plugs? Spark plug wires also, then on to sensors, I think you are due for some basic maintenance and repairs along with a mechanic that can analyze and replace appropriately.