Ok, so i baught an o2 sensor off some website, there were 2 options,both bosh.

And i knew that the o2 sensors for b13s have a rounded end and little slots going around the side of it. and the wire colors are red and white and black. so i ordered that one.

When i got the new o2 in the mail, i opened it up it has a flat top, and little holes around the outside, and the wires are blue black and blue i belive.But the connector fit into the cars harness so i put it in.

Now, i used to get 270 to the tank and when i would fill up i would put in anywhere from 10.5-11 gallons ok.

the other day i filled up after driving a whole tank with the new o2 in, and i filled up at 240 cause the light came on around 220 so i felt like i didnt wanna run out of gas:rofl: so when i filled up this time i pumped just over 12.5 gallons.

The o2 is the only thing i changed, then i got bad gas mileage. My question is, the o2 sensor that i was sent, could that have been a rear o2 sensor they sent me, or somthign?? i dont know!!!

bump HELP!!!!

u sure u got the correct one, zirconia vs titania issue?

I have a new and an old O2 sensor just how you describe. Both Bosch but very different looking. The one with the flat top is brand new. It also has the same part number as the old one. NAPA could be wrong! Let us know what you find out. I just installed it, so no feedback.

Unplug the battery for a period of time, I forgot how long, to reset the ECU of any codes and initiate relearn...or reset it at the ECU by the turn screw..

L

ok, thanks, *** try the reset. i have notcied a slight gain in mpg from when i first changed it, so maybe i just need t reset it. ill keep ya posted