The AC signal is not necessary, It will always assume the AC is off. The downstream O2 is necessary, or a dummy sensor, with dummy heaters. Otherwise the MIL will come on. Also, the ECU will not go into closed loop. That is a function to protect the cat. The engine will run alright, but you will lose performance. I am sure you could fake out the EGR system, but it would be easier to just leave it. As for EVAP, it will be difficult to fake it into thinking it is working properly. It can probably be done. I dont know if EVAP codes will keep it out of closed loop, so performance may not be affected. The Vss is important. There are aftermarket devices available to create a vss signal. If the vehicle was equipped with a 22re ( i know nothing of Lotus) there may be a VSS in the existing Spedo. Hope this helps.
