Just got trouble code p1646. Do I just need to replace it. Where is it located and is it o.k. to use the car until then. Thank You for your help.....mick99

 

You can still drive that car. Long run I would get it fixed though. I think that is for UPSTREAM sensors (left and right, forget which one it is based on the code) which are somewhat easy to replace on your own if they are not rusted in. If you look at the back of the motor where the exhaust pipes come in you will see one on each side go into exhaust right about the cats, those are the upstream ones, downstream after the cats. Others will chime in but I am sure that code is for upstream. I would make sure all the wires to them are snugly fitted, nothing pulled out or the like which would throw the CEL. Still you can drive the car but I would fix it, don't drive it that way for a year. They both plug in at the back of the motor above the trans, can be hard to see and get too.

 

It's actually important to change it soon. The ECM will have the engine running on rich startup mixture. It's the upper right one. Check the below link for an easy access method.

https://www.jaguarforums.com/forum/x...cement-115991/

 

yes it will run rich but it does not mean he has to park the car till it is fixed.

 

Note I said soon, not park the car.

 

Change it soon as it'll run rich and be damaging the cat conv.