Hi, anyone have any experience with deleting the centre resonator on an XJR (01/02) and replacing it with a Magnaflow x-pipe? In this case, doing so seems to have thrown a CEL with code P1647. Said code points to oxygen or Lambda sensors.

Any thoughts much appreciated!

 

That code is for the left bank upstream sensor. It may be coincidence, but try swapping the connector with the right bank upper and see if the code reads the same, or just compare the resistance of the two.

 

I’m with RJ. Definitely a coincidence. It’s not like you took out a catalytic converter and then your light came on. It’s most likely an open heater circuit within that 02 sensor anyways.