it does sputter, but it also idle's rough. not sure on if the ecu grounds or not. i don't think it does. not sure though. when i took my truck into the ref after the 22re swap, he unbolted the ecu while the truck was running and pulled it away to read the serial# on the back to make sure it matched. i would gues probably not on grounding to the body. i do know there is a couple of pig tails for the injectors that ground to the intake.
if your motor only has 10k miles on it, i would definitley check the valves for adjustment. for some reason, the hand full of toyota's i have worked on, the valves seemed to tighten over time rather than loosen up like you would expect. s
start with what doesn't cost anything, and work your way from that. the valve adjustment might not be the sputter problem, but it sure sounds like it is with rough idle. hopefully the sputters not froma burned valve from running the rockers too tight. here is the order i would do it in...
1. Check valve/rocker arm adjustment
2. Check compression, even if you did it recently
3. Check to make sure all your grounds are connected
4. Check EGR to make sure it is functioning properly(this can cause a sputter if plugged up); what I did with my egr to see if it was working or not when i had a miss/sputter was plug off the vacuum lines going to the diaphram and drive it around to see if it goes away.
5. Check fuel pressure
6. Start spending money....