Well, i think the E-test does give you an afr at 2000RPM or something but you're looking for consistancy during the RPM range. Get a dyno done. Dont worry about the chip, your car has knock sensors, it will retard the timing if need be.
Hot: 2001 Estoril M Roadster
ZCP 19's, ZHP knob, JL 8W3
Cold: 2002 TiAg M3 6mt
ZCP 19's supersports, ZHP knob, UUC short shift GROM, OEM 18's w310's,
http://absolutehid.ca hid kit