Just bought this car with a 2000 LQ4 6.0.
It had a lag/stumble on a fairly hard acceleration, and after a scan my knock sensors were apparently out. I replaced both, cleared codes, and reset ECU (battery disconnect).
Now I can feel it missing on low end acceleration.
Checked fuel pressure (not volume) and it was within specs.
Previous owner said he had a shop do a tune, change injectors, pump, and a coil, so at this point I have no idea what was installed. New owner of shop, with no records.
Any ideas where to start?
Thanks

 

If it has headers, start it up, and after 15 seconds or so of running, use your infrared temp gun to see if any tubes are cold.

 

Thanks, will give that a shot.
Should let me know if a coil or injector is not working on a cylinder.

 

Thank you so much for the suggestion.
Borrowed my friends temp gun and one of my cylinders was 200° cooler after 3 to 4 minutes of running.
I already had an order in for new plugs and wire, so I just added a new coil to the order. Hopefully that will take care of it.
Thanks again.