I got a reader from autozone, and it pulled these

P0171
P0174
P1642
P1000

from my 2000 XJR


so, I'm looking for guidance fuel pump/filter maybe?

 

just checked the intake pipe and seal with the throttle body, both good, couldn't find a leak with my eye anyway. MAF was just replaced, which fixed my hesitation and poor performance issues

 

You have a vacuum leak of some sort. The code reader you bought, does it just read codes, or can you look at some live data? If you can, look at the ltft and stft on both banks. Look at them at idle, then carefully under a heavy acceleration see what they read, may be better to have someone else drive.
On the R there are many places for the vacuum leak. Look at fuel trims first, then let us know. Also, clear the codes before checking that.

 

Intercooler O ring seals?

 

What's the CAN circuit malfuntion code for? (p1642)

 

the code scanner is just a loaner from autozone.. only scans, doesn't monitor live unfortunately.

since I removed/reseated the throttle body/intake manifold junction earlier today, I haven't had the problem again, and I've driven probably twice as much as I had when it was cropping up earlier. that doesn't mean it's fixed of course... but it could have just been loose and letting air in. Should there be any grease on that seal? I assume not, looks like it just fits dry. I will talk to someone local and see if I can get them to read some data for me

thanks!

 

the joints between the SC output and the intercoolers? they look good, I think.. the seals seem to be correctly in place

 

got failsafe mode, code P0121

I saw there was someone else who had a similar problem which was the result of the metal in the TPS sensor pins being mismatched.. one side was gold and the other was tin.. not sure where that sensor is to check the pins