There should be a Letter Prefix prior to the number such as P or C. A P1647 indicates a problem with the left (driver)bank front 02 Sensor. If defective, generally members recommend a Genuine Denso replacement. Various vendors on NET have it available less then $100.

 

Just bought a 2003 XK8. Day 2 I have a code 1647 Where can I find the fuse to check with the hope that an easy fix is possible?
is the vehicle safe to drive with this code ?
Thanks

 

P1647 indicates an O2 Sensor heater malfunction. Most likely its the sensor itself. Causes an emission problem because after cold start it takes a bit longer to get the O2 Sensor on duty.
Depending on the mileage (90.000 +) i would have changed both pre cat o2 sensors.

Fritz

 

Appears a duplicate thread. I replied to the 1st one.

 

realized that too late, but we mostly have the same opinion.

fritz