Welded in a big Ford truck cat, wired an O2 sensor into the ECU harness and ran a US M5 ECU. Passed pretty easily. Now to remove the cat, put the Alpina resonator back in and run the euro ECU again. With all this stuff on it, the car felt no faster than a 535i with a chip and a 3:73.
Thank God for the M88/3, no cat and a euro ECU with software.
Forgot to mention that I am interested in buying a 079 ECU. This is a US M5/ECE KAT version. Any US M5 or M6 will be running one. Would like to have one on hand for emissions testing when I need it.
A big thanks to Mark Osier from the 6 board for allowing me to use one of his.