If I have a bad O2 sensor, will it automatically trip an SES light on my 94 Z?

I have no experience with the things, so I don't know what the replacement interval generally should be. Also I don't know when or if the previous owner replaced them. Im at 95K miles on the car w/ about 30K on the motor.

I'm getting pretty poor mileage (~14-15 around town) and wanted to start ruling things out.

Plugs and wires are less than 6 months old, and the engine runs perfectly.

It's probably just all in my right foot.

 

I believe the only way an O2 sensor will trip a SES light is if it is disconnected or has an open in the sensor and/or harness. O2 sensors get coated with age making them less sensitive to changes in O2 readings. You car will burn richer as the sensors age, hosing up your fuel mileage. I'd just replace them, you can get them from any of the GM parts discounters (Dal, Jason Cromer, Team Chevy) for $35 each.

 

Probably a good maintenence type thing to do regardless, eh?

I'll put it on my to do list next time I have th car up in the air.

Thanks