How can tell if my car is running rich or lean without a A/F gauge?

I know that the exhaust gas from rich is cooler and lean is hotter, but what about engine noise?

Will a lean mixture cause the engine to run louder and rich to be more quiet?

If I am running rich, is there a way to tune the mixture short of a Safc?

thx

 

If you have no cats, you'll smell the gas in the exhaust. With my car it can make your eyes start to tear. Depending on how rich and if you have no cats you should be able to shoot flames. Also you'll get carbon build up quicker so you'd might see some black smoke when you are accelerating quickly.

 

Hook up a multimeter to the O2 sensor either at the ECU or right from the O2 in the engine compartment. Measure the voltage reading. Jay