What's the Jaguar XJ8 fault code p1647?

If You're getting diagnostic trouble code (DTC) P1647 in the Jaguar XJ8, it indicates that You've got an issue with Your Bank 2 oxygen sensor. This is the upstream oxygen sensor, which is located on the left side (driver's side, for LHD vehicles). You'll most likely find a failed O2 sensor itself, but may also find that the harness is open or shorted, or that the circuit has a poor electrical performance. With that said, the cost for replacement is predictably quite high. If You use a professional mechanic, You can expect to pay upwards of $500. The good news is that this is largely labor, though; the parts can be found for around $100 to $150, so if You feel confident enough to make the swap Yourself, the costs suddenly become more reasonable.