I have a 2000 Jaguar S type 3.0 liter and I have the following codes PO135,PO153 and PO155. I replaced three of the four O2 sensors but with this model and vin they say I need the curved O2 sensor but I can't seem to find it. Please any help is appreciated.

 

I've never heard of a "curved" O2 sensor, not that my limited experience means anything. What reference do you have calling this out? I just did a quick check at RockAuto. They list one part number for the upstream sensors, and a second number for the downstream side.

Have you already replaced them? Make sure you get vehicle-specific sensors with the correct connectors. Stay away from the universal models that require splicing the wires. Those are usually low quality.

Details about your codes here:

JagRepair.com - Jaguar Repair Information Resource


Note the second digit in each code is the number 0 (zero), not the letter O (as in October). Lots of good info in the forum available with the search function. However, searching for PO135 won't find much, but P0135 will.

 

Curved? Weird. What do you mean?

You need exactly the right kind of sensors plus check the circuit.