Please excuse me starting yet another P1647 thread but, having spent a week or two reading previous ones, I haven't come to any conclusion or found a solution (as yet).
So, the car is a 2005 X400 with manual trans and the 2.5 litre V6.
After replacing the crank position sensor, to fix a P0335 code, I now have a persistant P1647, indicating problem with the HO2S in bank 2 upstream. Also there are P0300, P0302, P0304, P0306, P1314 and P1316 coes indicating severe misfiring - and the car misfires badly when run.
I replaced the upstream HO2S on bank 2 - quite a fiddly job - but, instead of solving the problem it appears to have made it worse !
Unless I have been sold a faulty sensor, then this seems to indicate that something other than the sensor is at fault.
My question right now, before I throw money at another sensor, is: Is there any condition other than a faulty sensor which can throw up a P1647 code ?
I wondering whether some other fault can cause the sensor to give 'out of range' readings and thus cause a P1647 to be logged ?
Thanks in advance.

 

It can be a fuse/relay/wiring/etc fault but of course could be the wrong kind of sensor (several types are available) or a faulty one.

 

Thanks, JagV8, for the swift reply.
Visual examination of the wiring shows it to appear to be in fine condition. The fuses involved are fine - I actually checked all the fuses in engine bay fusebox while I was there.
Do you know of any way I can check/test/prove the sensor without the expense of buying another ?
Thinking of diagnosis, I do have an ELM327 bluetooth OBDII unit and have loaded the 'Torque' app onto an andriod tablet. I am guessing that I could use this arrangement to monitor various things while test-driving the car to help track the problem down, perhaps ?
Of course, that leads to the question: What should I be monitoring and expect to see ?
Thanks again,
Kevin.

 

I'd usually just swap side to side. Fault either stays with sensor or not...

 

Thanks again, JagV8, sounds like I should try that.
Not a task I am going to relish as replacing the upstream HO2S on bank 2 was fiddly enough the first time around - - - I just hope the bank 1 one is not quite so awkward !
Actually, I'm a little surprised at the way what should be relatively straightforward jobs seem to involve all kinds of dismantling on this car. Not exactly what I expect with a Jaguar as all the others I have owned have been pretty easy to get at, even the X300 Sovereign. By comparison, the X400 engine bay seems pretty cramped and not so easy to work on.
Anyway, thanks again and I'll report back later.

 

Smaller cars get things shoehorned in and some parts are awkward to access.

 

You're dead right there, JagV8 ! That HO2S upstream on bank 2 was a nightmare to get at
One of the many reasons why I choose to run Jaguars is that access for maintenance and repairs is mostly pretty straightforward and logical. The X-type doesn't really seem very much smaller than the X300, except in one place - - - the engine bay.
A few more inches here would have made a lot of difference, I think.
The air filter appears to have been put in the only space with room left for it, and whatever happened to having the battery sensibly tucked out of the way at the rear of the car ?
I feel that a slightly longer 'front end' would have helped with engine bay room immensely - and also improved the look of the car too.

 

I bought the bigger S-Type... so far so good, more room... but with the STR engine. Oops, no room at all!!

(Although it happens the O2s are good access.)