Oxygen sensor question for my truck

Factual Questions
1

I have a 2002 Toyota Tacoma with a v6, automatic transmission. The check engine light recently came on and the code read P1135, which points A/F Sensor Heater Circuit Malfunction (bank 1 sensor 1). So the guy at the counter has to order the part which comes in a few days later. I pick it up and he has sold me the wrong sensor. I have the downstream o2 sensor, not the upstream. I went online, searched for the correct part, and based on the price this confirms the guy sold me the wrong part. The upstream sensor cost twice as much as the downstream.

My question is this: Can I replace the bad upstream sensor with downstream sensor I have, splice the wires onto the old upsteam wires (in order to use the existing connector) and everything work correctly? I would like to avoid spending another $80 to $90 if possible. But, I would like to know why an upstrem sensor cost is so high.

Any information on this would be appreciated

-Jacob

2

Dream on…

The sensors are different. The downstream sensor is heated.

3

The upstream sensor is in the exhaust manifold, before the catalyst. It is the one used for engine management functions. The downstream sensor is in the exhaust pipe after the catalyst, and is primarily there to make sure the catalyst is functioning properly. As beowulff says, the cost difference is likely due to one being heated. Though I think the upstream one is the heated one since it would help to get the engine into closed loop sooner.