ok so i heard dont buy bosch. why not..? and if i dont buy that then whats a good one to buy.

Im getting shitty milleage so i thought id start with the 02 sensor.

and which one do i replace the one before or after the CAT

i also have been reading use premium for better milleage, is there any truth to this?

Bosch just don't last in Bonnevilles, who knows why. Get a Denso from RockAuto.com

you could replace both, but I'd start with the front one.

i bought a Bosch and it went bad 4 months later.. many others have had similar experiences. The few bucks you save isnt worth it if it keeps going bad.

thanks guys

rock auto didnt have a denso. only bosch and acdelco

Get ACDelco then

ok thanks.

There'* definitely a lot of truth to using Premium on this engine. Hell, I even noticed a big difference between using cheap premium gas and good premium gas (Cheap meaning places like Speedway, and good meaning places like Phillips or Shell). I always pump Shell or route 66 (Phillips) here in IL because I know they're clean gasolines, and I generally get 25 average highway fuel economy, which drops down to about 17 in the city under mild driving.