O2 Sensor (Bank One)

My check engine light has been on and now my gas milage went from 300 a tank to 254 tank. I'm trying to figure out the correct one to replace. I think it is the sensor before the cat. Any advice? Best place to by a good replacement. I hear Bosch is a good replacement.

I had to replace the starter @125,000 but other than that she's been reliable.

I love my Tacoma and want to make it last. I tow a little, drive off road a little but mainly highway. My 99 has 135000 and I hope I can get to 265000.

Forest Green 99 4wd v6 with Shell.

 

I just found two great sites in my search for the O2 sensor.

Auto Parts Wharehouse 800 859 0923

Parts Store Discount Toyota Parts 888 231 5293

I got my oem Bosch o2 sensor for $90 they listed it for $99 they will negotiate.