Hey guys thanks for this awesome forum. I've already fixed the ABS control module (resoldered power pins) and the cup holder due to the very helpful posts I found after a quick search here. I just bought this few days ago. It came with plenty of issues but also practically given to me. Its a beautiful black 99 XJ8L that has been taken care of most of its 81K miles but the lady got too old to drive it and just let it sit for a long time with no use in her garage.
So I could use some advice from the experts here on how to proceed with my check engine light. I took it to autozone(have a bluetooth OBDII on the way) and these are the codes it gave me.
P0333 Knock Sensor 2 circuit High Input
P1647 Heated Oxygen Sensor Control Module Bank 2 Open / Shorted
P0300 (which I think refers to another code) Random Multiple Misfire
P1316 Misfire Rate Excess Emissions

Are these all O2 sensor issues?

 

DTC guides for you.

bob

 

Since you don't know when the DTCs were logged in the ECM, I would clear them and drive the car to see if any recur.

bob

 

Thanks guys I will clear them and refer to the documents you attached for more information