N00B O2 questions, O2 locations, quantity, & replacement Options

[MSKapcala]

I have some questions on the O2 sensor locations in my 1997 GT 2.2L. I ordered 2 new oxygen sensors, the "upstream" and "downstream" (thank you Rock Auto). I googled online and looked for videos, but couldn't find any info on this generation (as far as the sensor locations and how to replace).

I found a picture on the forums here. Is the top one the "upstream" and the lower one the "downstream"? Most of what I see online for other cars or generations of celica say the "downstream" is in the exhaust and under the car. This is why I am confused... Parts websites only list 2 O2 sensors for this car and they look like what is in the picture. I am struggling to find out how to post the picture, but it can be found in this link on this forum - http://www.6gc.net/forums/index.php?showto...sor+replacement


Any help would be greatly appreciated. Thanks!!

[njccmd2002]

Lol, why change them? Get under your car, follow the exhaust. You’ll find the sensors. You need a mechanics tool available at hardware store to remove the sensor. Some cars have one, some have 2. Depends on year model.

[MSKapcala]

Lol, why change them? Get under your car, follow the exhaust. You’ll find the sensors. You need a mechanics tool available at hardware store to remove the sensor. Some cars have one, some have 2. Depends on year model.

I’m replacing because the car has 255k miles and from what I can tell they have never been replaced. I also don’t think I’m getting the mpg I should be. I ordered the special socket/tool. Can’t get under the car right now as it’s parked next to a curb in the road by my house and I can’t drive it to move it since the intake of ant hooked up.