I have a 96 SC300 and I need to know which o2 sensor is "bank 1 sensor 1".

When I lift up the hood I can see 2 02 sensors coming off of the exhaust manifolds. Would it be the one closer to the front of the car or closer to the back of the car?

I hope I don't sound like an idiot...I don't really know what I am talking about, but I am going to buy the part on oxygensensors.com and I want to make sure my mechanic sticks it in the right place. Thanks!

 

Usually, Bank 1 refers to the RIGHT side sensor, or, in the case of your straight six, there will only be the one bank (1). Sensor 1 IS the critical one, and it is the one closest to the engine... this is the sensor that actually sends air/fuel ratio info to the ECU for adjustment of fuel flow. Sensor 2 is further downstream, and exists mostly just to report on how well the Cat. converter is doing its job to reduce emissions. When unacceptable emissions get through that unit, then you'll get a "bank 1 sensor 2" error code, which doesn't necessarily affect engine performance, but does indicate you're putting out nasty emissions.

Make sure you order the correct sensor, as sometimes the function and design of the two are different

 

Does anyone have the part number for that particular sensor?