Hello community,
I am looking for an advise, as this place has heaps of information to help DYI.
I am new to Jaguars, just always wanted to have one; as song goes "...long and black..."
The car is 04XJ8 VDP. 46k miles
Everything was going fine until last week For all the sudden idling became rough, then MIL comes on and "reduced performance" message.
Following DTC:
P0301
P1313
P1316
Yea, I drove it home and there is one steep hill...
Before I start through parts at it, could it be water in gas tank? Car sits most of the week and gets out only on weekends.
Then I would think that misfire would be registered on more than one cylinder.
Battery measures 12.26 with engine off and 14.56 with engine running.
What are chances of bad gas or water in gas?

More likely you simply have a bad spark plug or a failed coil pack just affecting cylinder 1.
The P1313 and P1316 are most likely just the O2 sensors on bank 1 reporting the presence of unburned fuel reaching them, resulting in ECM restricting engine performance to reduce likelihood of catalytic converter damage.
If you don't want to give it a birthday and shout it some new plugs just now (you would normally hope for 75-100K out of a plug set), then alternatively you might like to just swap the No.1 coil pack over to another cylinder to see if the fault code P0301 changes to represent which cylinder you have moved that coil pack to.
At least you would have proven a defective coil pack and can replace accordingly.

what he said….and it is an easy swap…

Thanks both you folks!
You just confirmed what I was leaning to! This is easy check too, just few of bucks and may be some pain removing old spark plugs. I will do it this weekend and report.

Mark

OK, Just wanted to report:
Past weekend spark plugs and coil packs arrived. I decided to replace all 8, just to reset the clock.
I could not get iridium plugs in time, so here is what I went with:

Working on 18 years old car is like walking on egg shells!
I was very careful with all plastic hoses, just disconnected them, very carefully, in case if wrench slips, even then, I was controlling force on wrench not to let it snap in to something even benign; no sudden moves with tools in hand, not to snag on something important. Nice to grow zen !
I was surprised, that coil cover with jaguar logo on driver side survived me pulling it all the way forward.... That definitely exceeded my expectation on how much deflection this old plastic can take.
That spring lock connector on driver side puzzled me as it was first time I saw one! Eventually I left it along, probably to the best. On other hand the plastic vacuum hose, I think it goes to the break booster, I would like to know how to disconnect it from fitting that comes from break cylinder compartment. Very probable I will have to return here to replace valve cover gasket: from underneath, front end of engine and transmission oil lines on drive side are more wet than I would like to see.

Any way, task at hand: issue was corrected it was bad coil on cylinder #1. The DTC code changed from P0301 to P0305, when I swapped coils between #1 and #5.
Not trouble codes,
Monitors complete 4
Monitors not complete 4
P1000 that is ok until all monitors set.
Anybody knows if "monitors not 'equipped(?)' =2 is this 2 included in 4 that are not complete?
Wife inspected, tested and approved!

Thanks everybody for moral support
Mark "Большая Кошка"