just put in a new precat o2 sensor.

i disconnected the battery, and when i fired it back up, the CEL went out and hasn't come back...

the car runs smoother, pulls harder, BUT, it seems like the gas mileage isn't what it should be, per the DIC, and it smells like it's running rich.

is this just the car feeling itself out? or could i have crossed a wire or what?

 

What brand of O2 sensor did you use?

If you say anything other than AC Delco.... that could be your problem.

 

"pulls harder", Sounds like you drove it like you stole it, hence the MPG going down. As far as running rich, I highly doubt that. You'd be getting a CEL and see black smoke. You don't have to use AC Delco O2 sensors, Denso and Bosch would work with no problem its all the same ****.

 

that's not it, i'm saying that it pulled harder with easy throttle.

i'm going to check my wires, i bought a bare sensor and soldered the OEM connector onto it, i may have just reversed the two wires and it's freaking out