How many o2 sensors do I have?

[LexusES250]

Hello all,

I have a 1990 ES250, and was wondering how many o2 sensors I have? I was told that I only have an up stream one, but just want to be sure about it. Any one have web sites with pictures on where this one is located. I know it's behind the block, but where? Thankyou all in advance.


Bart

[EKam]

It's between the exhaust manifold and the cat.

[LexusES250]

any pics?

[LexusES250]

Ok so I found it right next to the oil filter. I bought a universal Bosch o2. Wondering which wires need to be spliced because I only see one coming from the back of it. Is it a single wire style o2 sensor? If so which wires do I need to connect? Would a single wire o2 work at the moment I have a 4 wire on? Thank you for your help in these matters

[KS_Hicks]

That is not you o2 sensor next to your oil filter. That is you oil pressure sender. That is what sends the signal to your light on your dash. Your o2 sensor is located between you rear exhaust manifold and you converter. If you follow you rear exhaust manifold down it is located on the on the side of the manifold. It should be just a little bit before you reach where the flanges connect.

[BLUEMEANIE]

^ what he said