ur main problem with that is making sure what 2.2 you have. some newer ones in the states came with crank sensors (i wanna say mid 2006+). the lsj has crank sensors [one of the reasons no one has transplanted a lsj into a cavalier (02-06 2.2)] there were/is other problems but i really dont know much about the diff between the 2.2 and lsj as far as transplanting goes.
yes you 'could' transplant the ecu to a us spec one but its a HUGE pain in the ass. just as bad as doing a standalone. esp because its not a us spec car so i dont know if it'll have the same sensors. also getting the inspection ect might be a hassle since its not up to UK specs. the best thing for you to do is get the lsj engine and wiring harness/ecu from the same car. this helps also if the ecu is thinking its going in a manual and turns out its going in a auto or if it thinks it has abs and doesnt.
if you're not on it already try asking around in the ecotecforum.com forums a good handful or more guys there know 100x the stuff i do. plus many of them have looked into transplanting a lsj so they know what the problems are and potential solutions.
the ecu should have the passlock system but im not sure if you have to take it to a dealer to get it unlocked of if you can do it on your own. i know with the old passlock system (2003) all you had to do was a specific "code" with turn the key to acc and back. also be prepared for the fact taht your car will prob. have different sensors, wires, ect from the standard GM ones since the speedster is made by lotus. and the lsj are put together in the states by gm.
