I was running L6 with wasted spark on mine but still had no end of problems , spoke to my tuner and he recommended a link Ecu so swapped over to that and must say it’s the best thing I have done on the car , now closed loop running high and low boost switch with pretty much every safety feature built/mapped in to it you could imagine , I’m running 1000cc id’s and it still went straight through emissions test on mot .
I think upgrading to a new modern Ecu is a must , it has totally transformed my car to something that is almost modern to drive .