2000 jaguar xkr coupe. A month ago as I got off the highway I temporarily lost servo for brake and started missing badly at idle; shakes and missed so bad when I turned the car off it wouldnt start without flooding the gas pedal. "Limped" back home on highway ok but stalled at idle. Started a few times in the next week but still running badly at idle.

Ran JLR software and get the following codes
P1000, P0174, P0171: Lean bank 1&2
P0302-8 missfire 2-8 cylinders
P1316; missfire exceeds emission
Instrument pack: B1202 fuel sender circuit open; U1260/1 SCP (+-) failure

Troubleshooting:
1. At 80k mi, althought timing needs a service, if it were to jump, I would not make it home at all, plus rides ok on the highway. I plan to update the secondary tensioner soon but I need the car to run normal before I throw big buck parts in her.
2. Fuel: Changed both fuel pumps last month, quality ones too, auto parts store loaner tool fails to do the pressure test twice(bad device) but there is definitely fuel (seen it from the schrader valve when connecting)
3. that leaves unmetered air: (as chatgpt also suggested) but where can I start to find the vacuum leak. Throttle body? Bad sensor? Could also be MAF? or EVAP? How should I test for this?

Any pointers? Are there any common vacuum leak around the intake or where should I be looking at? I need to have this car running soon and drive long distance, would appreciate any wisdom from the group...

 

You really need to take the cam covers off and have a look at your secondary tensioners before you do anything else. If they haven't fallen apart yet, you can then update to the latest versions at very little cost, safe in the knowledge that your engine isn't going to self destruct.

At the moment, every time you turn the ignition key, you are gambling.

 

After that, check for air leaks e.g. check at-idle fuel trims.