When to buy O2's
 

At what time mileage wise should you replace the front 02's?

good question, I have 50k on my stockers and I think it could be time.

if u get a check engine light for them, or u notice poor mpg.

:werd:

12mpg is all I ever get any other clues?

just before you get a tune, i put in new ones at about 79k and they did make my tuning easier/more consistent. the milage went to shit, but that's because tuned car is so much more fun i get on the loud pedal too much ;)

Put your right foot on a diet? :)